הלכות ביאת מקדש פרק ה׳ Rambam · Hilchos Bias HaMikdash 5

מִצְוַת עֲשֵׂה לְקַדֵּשׁ כֹּהֵן הָעוֹבֵד יָדָיו וְרַגְלָיו וְאַחַר כָּךְ יַעֲבֹד שֶׁנֶּאֱמַר (שמות ל יט) "וְרָחֲצוּ אַהֲרֹן וּבָנָיו מִמֶּנּוּ אֶת יְדֵיהֶם וְאֶת רַגְלֵיהֶם". וְכֹהֵן שֶׁעָבַד וְלֹא קִדֵּשׁ יָדָיו וְרַגְלָיו שַׁחֲרִית חַיָּב מִיתָה בִּידֵי שָׁמַיִם שֶׁנֶּאֱמַר (שמות ל כ) "יִרְחֲצוּ מַיִם וְלֹא יָמֻתוּ". וַעֲבוֹדָתוֹ פְּסוּלָה בֵּין כֹּהֵן גָּדוֹל בֵּין כֹּהֵן הֶדְיוֹט:

It is a positive commandment for a priestThe Rambam emphasizes that this mitzvah applies to a priest, because an animal offered as a sacrifice may be slaughtered by a non-priest. Such a person need not sanctify his hands and feet. This explanation is reinforced by some of the versions of Sefer HaMitzvot (positive commandment 24) which state "A priest alone is obligated...," i.e., a priest and not a non-priest. who serves [in the Temple] to sanctify his hands and feetThrough washing them from the basin in the Temple Courtyard, as the Rambam proceeds to explain. and afterwards perform service,Sefer HaMitzvot (ibid.) and Sefer HaChinuch (mitzvah 106) consider this as one of the 613 mitzvot of the Torah. as [Exodus 30:19] states: "And Aaron and his sons will wash their hands and their feet from it." A priest who servesIf he does not perform service in the Temple Courtyard, he is not liable even if he enters without sanctifying his hands and feet (Rav Yosef Corcus). without having sanctified his hands and feet in the morningWith the latter addition, the Rambam excludes the extra sanctifications performed by the High Priest on Yom Kippur before and after the changes of his garments. If he does not sanctify his hands and feet at this time, he does not invalidate his service, as stated in Halachah 7. is liable for death at the hand of heaven,Nevertheless, as explained in Hilchot Sanhedrin 19:3, he is not liable for lashes, because he has only violated a positive commandment, not a negative commandment. as [ibid.:20] states: "They shall wash with water and not die." Their service - whether that of a High Priest or an ordinary priest - is invalid.

וּמִנַּיִן שֶׁעֲבוֹדָתוֹ פְּסוּלָה שֶׁנֶּאֱמַר (שמות כח מג) "חֻקַּת עוֹלָם לוֹ וּלְזַרְעוֹ". וּבְבִגְדֵי כְּהֻנָּה הוּא אוֹמֵר חֻקַּת עוֹלָם. מָה מְחֻסַּר בְּגָדִים מְחַלֵּל עֲבוֹדָה כְּמוֹ שֶׁבֵּאַרְנוּ. אַף מִי שֶׁלֹּא רָחַץ יָדָיו וְרַגְלָיו מְחַלֵּל עֲבוֹדָה:

Which source teaches that his service is invalid? [Ibid.:21] states: "It will be an eternal statute for him and his generations," and with regard to the Priestly garments [ibid. 25:43] also uses the expression: "An eternal statute."The text of the Mishneh Torah does not quote the verse exactly. Just as [a priest] who is lacking the priestly garments invalidates his service, as we explained,Hilchot K'lei HaMikdash 10:4. so, too, one who did not wash his hands invalidates his service.

אֵין הַכֹּהֵן צָרִיךְ לְקַדֵּשׁ בֵּין כָּל עֲבוֹדָה וַעֲבוֹדָה. אֶלָּא פַּעַם אַחַת מְקַדֵּשׁ בַּבֹּקֶר וְעוֹבֵד וְהוֹלֵךְ כָּל הַיּוֹם כֻּלּוֹ וְכָל הַלַּיְלָה. וְהוּא שֶׁלֹּא יֵצֵא מִן הַמִּקְדָּשׁ וְלֹא יִישַׁן וְלֹא יָטִיל מַיִם וְלֹא יַסִּיחַ דַּעְתּוֹ. וְאִם עָשָׂה אֶחָד מֵאַרְבַּעְתָּן צָרִיךְ לַחְזֹר וּלְקַדֵּשׁ:

A priest does not have to sanctify [himself] between every service [that he performs]. Instead, he consecrates [his hands and feet] once in the morning and may continue serving throughout the day and [the subsequent] night,On the following day, he must sanctify his hands and feet again, even if he did not sleep at night, as stated in Halachah 8. provided he does not: a) depart from the Temple;See Halachah 5. b) sleep;The Kessef Mishneh explains that this requirement is derived from the obligation to sanctify one's hands and feet if one diverts attention, for it is likely that while sleeping, one did divert his attention. c) urinate;See Halachah 5 with regard to defecation. or divert his attention [from his hands and feet]. If he does any of the above, he must sanctify his hands and feet again.

יָצָא מִן הַמִּקְדָּשׁ וְחָזַר וְעָבַד וְלֹא קִדֵּשׁ אִם לֹא הִסִּיחַ דַּעְתּוֹ עֲבוֹדָתוֹ כְּשֵׁרָה. וְזֶה הַכְּלָל הָיָה בַּמִּקְדָּשׁ אֵין אָדָם נִכְנָס לָעֲזָרָה לַעֲבוֹדָה אַף עַל פִּי שֶׁהוּא טָהוֹר עַד שֶׁהוּא טוֹבֵל:

If a priest departed from the Temple, returned and then performed service without sanctifying [his hands and feet], his service is acceptableThere is an unresolved question concerning this point in Zevachim 20b. Hence, the Rambam rules leniently (Kessef Mishneh). if he did not divert his attention.In the other three instances mentioned above, if he serves without sanctifying his hands and feet, his service is invalid (Kessef Mishneh). This general principle was followed in the Temple: No person would enter the Temple Courtyard to perform serviceThere is a difference of opinion among the commentaries if a ritually pure person who enters the Temple Courtyard without intending to perform service is obligated to immerse himself or not. unless he immersed [in the mikveh] even though he was ritually pure.

וְכָל הַמֵּסִיךְ אֶת רַגְלָיו טָעוּן טְבִילָה. וְכָל הַמֵּטִיל מַיִם טָעוּן קִדּוּשׁ יָדַיִם וְרַגְלַיִם. יָצָא חוּץ לְחוֹמַת הָעֲזָרָה אִם לִשְׁהוֹת בַּחוּץ יָצָא כְּשֶׁחוֹזֵר טָעוּן טְבִילָה וְאִם לַחְזֹר מִיָּד יָצָא] כְּשֶׁחוֹזֵר טָעוּן קִדּוּשׁ יָדַיִם וְרַגְלַיִם בִּלְבַד. וְאִם לֹא טָבַל וְלֹא קִדֵּשׁ וְעָבַד הוֹאִיל וְלֹא הִסִּיחַ דַּעְתּוֹ וְלֹא הִסִּיךְ רַגְלָיו וְלֹא הֵטִיל מַיִם עֲבוֹדָתוֹ כְּשֵׁרָה. הוֹצִיא יָדָיו חוּץ לְחוֹמַת הָעֲזָרָה אֵינוֹ צָרִיךְ לַחְזֹר וּלְקַדֵּשׁ:

Anyone who defecates must immerse himself [in a mikveh].See the conclusion of Halachah 6. Anyone who urinates must sanctify his hands and feet.
[The following rules apply when] one goes outside the walls of the Temple Courtyard. If he departed [with the intent of] staying outside for an extended time, he must immerse [in a mikveh].Even if he actually remained outside for a short time. If [his intent] was to return immediately, when he returns, all that is necessary is that he sanctify his hands and feet. If he did not immerse, nor sanctified his hands and feet and carried out [sacrificial] service, his service is acceptableThere is an unresolved question concerning this point in Zevachim 20b. Hence, the Rambam rules leniently (Kessef Mishneh). since he did not divert his attention, nor did he defecate or urinate. If he merely placed his hands outside the Temple Courtyard, he is not required to sanctify them again.

נִטְמְאוּ יָדָיו מַטְבִּילָן וְהֵן טְהוֹרוֹת. וְאֵינוֹ צָרִיךְ לַחְזֹר וּלְקַדֵּשׁ. נִטְמָא גּוּפוֹ בַּאֲכִילַת אֳכָלִין טְמֵאִין אוֹ שְׁתִיַּת מַשְׁקִין טְמֵאִין וְטָבַל אַף עַל פִּי שֶׁאֵינוֹ צָרִיךְ הַעֲרֵב שֶׁמֶשׁ חוֹזֵר וּמְקַדֵּשׁ אַחַר טְבִילָה. שֶׁכָּל טוֹבֵל מְקַדֵּשׁ יָדָיו וְרַגְלָיו וְאַחַר כָּךְ עוֹבֵד. וְאִם לֹא קִדֵּשׁ הוֹאִיל וְלֹא הִסִּיחַ דַּעְתּוֹ לֹא חִלֵּל:

If [only] a person's hands become ritually impure,This refers, not to ritual impurity prescribed by Scriptural Law, but instead, to certain states of ritual impurity ordained by our Sages that affect the hands alone. See Hilchot Sha'ar Avot HaTumah, ch. 8. he may immerse them and they are ritually pure. He need not sanctify them again.
If his body became impure because he partook of impure foods or drank impure beverages and immersed himself, even though he does not have to wait until nightfall [to become ritually pure],See Hilchot Sha'ar Avot HaTumah 9:9. he must sanctify [his hands and feet] after immersing himself, for everyone who immerses himself must sanctify his hands and feet [before] serving. If he did not sanctify [his hands and feet], his service is not desecrated since he did not divert his attention.

כֹּהֵן גָּדוֹל שֶׁלֹּא טָבַל וְלֹא קִדֵּשׁ יָדָיו וְרַגְלָיו בֵּין בְּגָדִים לִבְגָדִים וּבֵין עֲבוֹדָה לַעֲבוֹדָה בְּיוֹם הַכִּפּוּרִים וְעָבַד עֲבוֹדָתוֹ כְּשֵׁרָה. הוֹאִיל וְאוֹתָן הַטְּבִילוֹת וְהַקִּדּוּשִׁין אֵינָן שָׁוִים בְּאַהֲרֹן וּבָנָיו וְנֶאֱמַר (שמות ל יט) "וְרָחֲצוּ אַהֲרֹן וּבָנָיו מִמֶּנּוּ" דָּבָר הַשָּׁוֶה בְּכָל הַכֹּהֲנִים מְעַכֵּב שֶׁהוּא קִדּוּשׁ רִאשׁוֹן:

When a High Priest does not immerse himself nor sanctify his hands and feet between his changes of clothes and between his different services on Yom KippurSee Hilchot Avodat Yom HaKippurim 2:2 for a description of these changes of clothing, immersions, and sanctifications. and [continues] serving, his service is acceptable.He does, however, violate a positive commandment, because he does not perform the Yom Kippur service as prescribed (Yoma 30b). [The rationale is that] since those immersions and sanctifications are not applicable equally to Aaron and his sons,They are obligations of the High Priest (Aaron), but not an ordinary priest (his sons). as [Exodus 30:19] states: "And Aaron and his sons will wash from it." Only an obligation that is equally applicable to all the priests is an indispensable obligation, i.e., the first sanctification of one's hands.

קִדֵּשׁ יָדָיו הַיּוֹם צָרִיךְ לַחְזֹר וּלְקַדֵּשׁ לְמָחָר אַף עַל פִּי שֶׁלֹּא יָשַׁן כָּל הַלַּיְלָה. שֶׁהַיָּדַיִם נִפְסָלוֹת בְּלִינָה. קִדֵּשׁ בַּלַּיְלָה וְהִקְטִיר הַחֲלָבִים כָּל הַלַּיְלָה צָרִיךְ לַחְזֹר וּלְקַדֵּשׁ בַּיּוֹם לַעֲבוֹדַת הַיּוֹם:

If a person sanctified his hands on one day, he must sanctify them again on the following day even though he did not sleep at all that night, for the hands are disqualified because of the passage of the night. [Even] if he sanctified his hands at night and offered fats on [the altar's pyre] the entire night,I.e., he was continually involved in the Temple service. he must go back and sanctify [his hands] on the next dayAt daybreak. for that day's service.

קִדֵּשׁ יָדָיו וְרַגְלָיו לִתְרוּמַת הַדֶּשֶׁן אַף עַל פִּי שֶׁהוּא מְקַדֵּשׁ קֹדֶם שֶׁתַּעֲלֶה הַשֶּׁמֶשׁ אֵינוֹ צָרִיךְ לַחְזֹר וּלְקַדֵּשׁ אַחַר שֶׁהֵאִיר הַיּוֹם שֶׁהֲרֵי בִּתְחִלַּת עֲבוֹדָה קִדֵּשׁ:

If a priest sanctified his hands and his feet for the removal of the altar's ashes,Which is carried out at dawn (Hilchot Temidim UMusafim 2:11-12). even though he sanctifies them before sunrise,Halachically, depending on the different opinions, dawn is between 72 minutes and two hours before sunrise. Sunrise is the time when the priest should sanctify his hands. Nevertheless, in this instance, he has no alternative, since he is sanctifying them for that day's service and that service is performed before dawn. he does not have to sanctify them again after daybreak, because he sanctified them at the beginning of the day's service.

מִצְוָה לְקַדֵּשׁ מִמֵּי הַכִּיּוֹר וְאִם קִדֵּשׁ מֵאֶחָד מִכְּלֵי הַשָּׁרֵת הֲרֵי זֶה כָּשֵׁר. אֲבָל כְּלֵי הַחל אֵינָם מְקַדְּשִׁין. קִדֵּשׁ בִּכְלִי שָׁרֵת בַּחוּץ אוֹ בִּכְלִי חֹל בִּפְנִים וְעָבַד עֲבוֹדָתוֹ פְּסוּלָה. וְאֵין מְקַדְּשִׁין בְּתוֹךְ הַכִּיּוֹר אוֹ בְּתוֹךְ כְּלֵי הַשָּׁרֵת אֶלָּא מֵהֶן שֶׁנֶּאֱמַר (שמות ל יט) "וְרָחֲצוּ אַהֲרֹן וּבָנָיו מִמֶּנּוּ" וְלֹא בְּתוֹכוֹ. וְאִם קִדֵּשׁ בְּתוֹכוֹ וְעָבַד לֹא חִלֵּל:

It is a mitzvah to sanctify [one's hands and feet] from the basin.See the description of this utensil in the conclusion of ch. 4 of Hilchot Beit HaBechirah. If, however, one sanctifies them from a sacred utensil, the sanctification is effective. Sanctification may not, however, be performed with an ordinary utensil.I.e., one that is not consecrated. If one sanctified [his hands and feet] with a sacred utensil outside the TempleThe sanctification must be performed within the Temple Courtyard, for that is where the basin is located. Even though the sanctification need not be performed with water from the basin, it must be performed in the area where it is located (Zevachim 22a). or did so with an ordinary utensil within the Temple and then performed service, his service is disqualified. One does not sanctify his hands and feet inside the basin or a sacred utensil, but from them, as [implied by the verse]: "Aaron and his son's will wash from it;" ["from it"] and not "inside of it." If one sanctified [his hands and feet] in such a utensil and performed service, he did not desecrate it.

הִטְבִּיל יָדָיו וְרַגְלָיו בְּמֵי מִקְוֶה אֲפִלּוּ בְּמַעְיָן אֵין זֶה קִדּוּשׁ כְּלָל עַד שֶׁיִּרְחַץ בִּכְלִי. וּבְכָל כְּלֵי הַקֹּדֶשׁ מְקַדְּשִׁין בֵּין שֶׁיֵּשׁ בָּהֶן רְבִיעִית בֵּין שֶׁאֵין בָּהֶן רְבִיעִית:

If one immerses his hands and feet in the waters of a mikvehThere were several mikvaot on the Temple Mount. or even a spring, this is not considered as sanctification. One must wash them from a utensil. One may sanctify them using any sacred utensil whether or not it contains a revi'it.86 cc. according to Shiurei Torah; 150 cc. according to Chazon Ish. The Ra'avad states - and the Kessef Mishneh explains that this is also the Rambam's intent - that if one uses a small utensil, he must take the water originally from the basin.

כָּל הַמֵּימוֹת כְּשֵׁרִים לְקִדּוּשׁ בֵּין מַיִם חַיִּים בֵּין מֵי מִקְוֶה. וּבִלְבַד שֶׁלֹּא יִשְׁתַּנֶּה מַרְאֵיהֶן. אֶלָּא יִהְיוּ כַּמַּיִם הַכְּשֵׁרִים לִטְבִילָה. טִיט הַנָּרוֹק שֶׁהַפָּרָה שׁוֹחָה וְשׁוֹתָה מִמֶּנּוּ מַשְׁלִים לְמֵי כִּיּוֹר. זֶה הַכְּלָל כָּל הַמַּשְׁלִים לְמֵי מִקְוֶה מַשְׁלִים לְמֵי כִּיּוֹר:

All water is acceptable for the sanctification, whether water from a spring or water from a mikveh, provided its appearance has not changed and it is [thus] acceptable for immersion.As stated in Hilchot Mikvaot 7:1, if the appearance of water has changed, e.g., one poured wine or juice into it and changed its color, it is not acceptable for immersion. Mud that can be poured, from which a cow would drink,Since a cow will drink it, it is considered as water and not as earth. Compare to ibid. 7:3, 8:9. 11:2. can be used to fill the measure of the basin. This is the general rule: Any water that can be used to make up the measure of a mikveh can be used to make up the measure of the basin.A mikveh must be 40 se'ah in volume.

כַּמָּה מַיִם צְרִיכִין לִהְיוֹת בַּכִּיּוֹר אֵין פָּחוֹת מִכְּדֵי לְקַדֵּשׁ מִמֶּנּוּ אַרְבָּעָה כֹּהֲנִים שֶׁנֶּאֱמַר (שמות ל יט) "אַהֲרֹן וּבָנָיו" וְהָיוּ אֶלְעָזָר וְאִיתָמָר וּפִינְחָס עִמָּהֶם הֲרֵי אַרְבָּעָה:

How much water must there be in the basin? At least enough for four priests to sanctify [their hands and feet] from it, as [indicated by Exodus 30:19 which] mentions "Aaron and his sons." Together with him, there were Elazar, Itamar, and Pinchas, a total of four.Zevachim 21b cites Exodus 40:32 which states "And Moses, Aaron, and his sons will wash from it." "His sons" is plural indicating at least two, thus reaching a total of four. The Rambam, here and in his Commentary to the Mishnah (Zevachim 2) substitutes Pinchas for Moses. The Kessef Mishneh questions that explanation on two counts: Firstly, at the time, the basin was first used, Aaron's older sons, Nadav and Avihu, were still alive. Moreover, the priesthood had not been granted to Pinchas as of yet. Rav Yosef Corcus tries to support the Rambam's understanding, explaining that according to certain views, Moses did not serve as a priest when Aaron did, only in the seven days of preparation.

מֵי כִּיּוֹר נִפְסָלִין בְּלִינָה כְּמוֹ שֶׁבֵּאַרְנוּ. וְכֵיצַד הָיוּ עוֹשִׂין. מְשַׁקְּעִים אוֹתוֹ בְּמֵי מִקְוֶה אוֹ בְּמַעְיָן וּלְמָחָר מַעֲלִין אוֹתוֹ אוֹ מְמַלְּאִין אוֹתוֹ בְּכָל יוֹם בַּבֹּקֶר:

The water in the basin is disqualified if left [in it] overnight, as we explained.Hilchot Beit HaBechirah 3:18. What would be done [to prevent the water from being disqualified]? The basin would be submerged in a mikvehIn his Commentary to the Mishnah (Tamid 1:4), the Rambam explains that each night the basin would be submerged in a muchani, a large container which held a reservoir of water. This container was not a sacred utensil and hence the water it contained was not disqualified overnight. See Hilchot Beit HaBechirah, loc. cit., for a description of this container. or a spring and on the following day, it would be raised or it would be filled each day in the morning.

הַיָּם שֶׁעָשָׂה שְׁלֹמֹה כְּמִקְוֶה הָיָה. מִפְּנֵי שֶׁאַמָּה שֶׁל מַיִם הָיְתָה עוֹבֶרֶת בְּתוֹכוֹ מֵעֵין עֵיטָם. לְפִיכָךְ לֹא הָיוּ מֵימָיו נִפְסָלִין בְּלִינָה כְּמֵי הַכִּיּוֹר וּמִמֶּנּוּ הָיוּ מְמַלְּאִין הַכִּיּוֹר:

The "sea" fashioned by SolomonSee I Kings 7:23-26. This was a circular copper tank, ten cubits in diameter and five cubits deep. had the status of a mikveh,As II Chronicles 4:6 states, the priests would use it as a mikveh. because a channel of water from the Spring of AitemA mountain spring slightly south of Jerusalem. It was 32 cubits higher than the Temple Mount. Hence the water would naturally flow through a conduit built from it to the Temple. would pass through it.Usually, water contained in a utensil is not acceptable for immersion. Nevertheless, since water from a flowing spring passed through this tank, its water was acceptable [the Jerusalem Talmud (Yoma 3:8)]. Therefore,I.e., because it was connected to a flowing spring. its waters were not disqualified with the passage of night like the water of the basin and [indeed,] the basin was filled from it.

כֵּיצַד מִצְוַת קִדּוּשׁ. מַנִּיחַ יָדוֹ הַיְמָנִית עַל גַּבֵּי רַגְלוֹ הַיְמָנִית וְיָדוֹ הַשְּׂמָאלִית עַל גַּבֵּי רַגְלוֹ הַשְּׂמָאלִית וְשׁוֹחֶה וּמְקַדֵּשׁ. וְכָל הַחוֹצֵץ בִּטְבִילָה חוֹצֵץ בְּקִדּוּשׁ יָדַיִם. וְאֵינוֹ מְקַדֵּשׁ כְּשֶׁהוּא יוֹשֵׁב מִפְּנֵי שֶׁהוּא כַּעֲבוֹדָה. וְאֵין עֲבוֹדָה אֶלָּא מְעֻמָּד שֶׁנֶּאֱמַר (דברים יח ה) "לַעֲמֹד לְשָׁרֵת":

How is the mitzvah of sanctification performed? [A priest would] put his right hand on his right foot and his left hand on his left foot and bend over and sanctify them.I.e., a colleague would pour water over them; alternatively, he would stand under a tap.
See Hilchot Nesiat Kapayim 15:5 which states that one would wash until the wrist. All the substances that are considered as intervening with regard to immersion,As explained in Hilchot Mikvaot, ch. 2, no significant substance may intervene between the flesh of the person immersing and the waters of the mikveh. That chapter details those substances that are considered as significant and hence, as intervening, and those which are not. are intervening with regard to the sanctification of hands.
One may not sanctify his hands while sitting, because [the sanctification] is comparable to the Temple service and the Temple service may be performed only when standing, as [Deuteronomy 18:5] states: "To stand and to serve."In the Rambam's Commentary to the Mishnah (Zevachim, loc. cit.), he offers another rationale: that one is not allowed to sit in the Temple.

וְכָל הָעוֹבֵד וְהוּא יוֹשֵׁב חִלֵּל וַעֲבוֹדָתוֹ פְּסוּלָה וְאֵינוֹ לוֹקֶה. מִפְּנֵי שֶׁאַזְהָרָה שֶׁלּוֹ מִכְּלָל עֲשֵׂה הִיא. וְכֵן כָּל הָעוֹסֵק בַּעֲבוֹדָה מֵעֲבוֹדַת הַמִּקְדָּשׁ צָרִיךְ שֶׁיִּהְיֶה עוֹמֵד עַל הָרִצְפָּה. וְאִם הָיָה דָּבָר חוֹצֵץ בֵּינוֹ וּבֵין הַקַּרְקַע כְּגוֹן שֶׁעָמַד עַל גַּבֵּי כֵּלִים אוֹ בְּהֵמָה אוֹ עַל רַגְלֵי חֲבֵרוֹ פָּסַל. וְכֵן אִם הָיָה דָּבָר חוֹצֵץ בֵּין יָדוֹ וּבֵין הַכְּלִי שֶׁעוֹבֵד בּוֹ פָּסַל:

Anyone who performs service while he is seated, desecrates his service and disqualifies it. He does not receive lashes, because the warning against doing so stems from a positive commandment.And lashes are given only when a negative commandment is violated.
Similarly, anyone involved with one of the Temple services must be standing on the floor.Zevachim 24a relates that since both the Temple utensils and the ground of the Temple Courtyard have been sanctified, an equation is established between them. Just as there can be no intervening substance between a priest's hand and a sacred utensil, so too, there may be no intervening substance between his feet and the Temple Courtyard. If there was anything intervening between himself and the ground,I.e., the stones of the Temple or the Temple Courtyard. e.g., he was standing on a utensil, an animal, or a colleague's foot, [his service] is invalid. Similarly, if there was anything intervening between his hand and the utensil with which he was performing the service, it is invalid.This is derived from Leviticus 4:5: "And the priest shall take." Implied is that the taking must be performed by the priest's body without any intermediary (Zevachim, loc. cit.).

וְאֵין עֲבוֹדָה אֶלָּא בְּיָמִין. וְאִם עָבַד בִּשְׂמֹאל פְּסוּלָה וְאֵינוֹ לוֹקֶה. רַגְלוֹ אַחַת עַל הַכֶּלִי וְרַגְלוֹ אַחַת עַל הָרִצְפָּה [רַגְלוֹ אַחַת עַל הָאֶבֶן וְרַגְלוֹ אַחַת עַל הָרִצְפָּה] רוֹאִין כּל שֶׁאִלּוּ יִנָּטֵל הַכְּלִי אוֹ הָאֶבֶן יָכוֹל לַעֲמֹד עַל רַגְלוֹ אַחַת עֲבוֹדָתוֹ כְּשֵׁרָה. וְאִם לָאו עֲבוֹדָתוֹ פְּסוּלָה. קִבֵּל בְּיָמִין וּשְׂמֹאל מְסַיַּעְתּוֹ עֲבוֹדָתוֹ כְּשֵׁרָה. שֶׁהַמְסַיֵּעַ אֵין מַשְׁגִּיחִין עָלָיו:

The Temple service may be performed only with one's right hand.Indeed, in his Commentary to the Mishnah (loc. cit.), the Rambam writes that "Whenever the word "hand" is mentioned [with regard to the Temple service], the intent is the right hand."
The above is referring to a right-handed person. A left-handed priest is disqualified from serving in the Temple, as stated in Chapter 8, Halachah 11. If one performed service with his left hand, it is invalid. He is not liable for lashes.For there is no explicit prohibition that he violates. Instead, it is an extension of a positive commandment (Kessef Mishneh).
[The following laws apply when] one of [a priest's] feet are on a utensil and one is on the floor, one is on a stone [that was not embedded in the floor] and one was on the floor. We evaluate [the situation]. Whenever he would be able to stand on his one foot if the utensil or the stone were taken away, his service is acceptable.For then, the support provided by the second foot is not of consequence. If not, his service is invalid.For then it is significant.
If he received [blood from a sacrifice] with his right hand and his left hand is supporting it, his service is acceptable, because we do not pay attention to [something that is] a [mere] support.This is a general principle, applying in other situations as well (see Shabbat 93b).

נִתְנַדְּדָה אֶבֶן מֵאַבְנֵי הָעֲזָרָה לֹא יַעֲמֹד עָלֶיהָ בִּשְׁעַת עֲבוֹדָה עַד שֶׁתְּחֻבַּר בָּאָרֶץ. וְאִם עָבַד עֲבוֹדָתוֹ כְּשֵׁרָה הוֹאִיל וּבִמְקוֹמָהּ עוֹמֶדֶת:

When one of the stones of the Temple Courtyard has become loosened, one should not stand upon it during one's Temple service until it is affixed in the ground.As long as it is not fixed in the ground, the stone can be considered as a separate entity and therefore, it could be considered as an intervening substance between the priest and the earth. If he performed service, his service is acceptable,There is an unresolved question concerning this issue in Zevachim 24a. Hence, the Rambam does not rule stringently. See also the commentaries to Hilchot Beit HaBechirah 1:10. since it is located in its place.