מִצְוַת קִדּוּשׁ יָדַיִם וְרַגְלַיִם בִּשְׁעַת עֲבוֹדָה – לִרְחֹץ (סהמ"צ להרמב"ם עשה כד) הַיָּדַיִם וְרַגְלַיִם בְּכָל עֵת הִכָּנֵס לַהֵיכָל (עי' תוס' יומא ה ב בד"ה להביא) וְהַבָּא לַעֲבֹד עֲבוֹדָה, וְזֹאת הִיא מִצְוַת קִדּוּשׁ יָדַיִם וְרַגְלַיִם, שֶׁנֶּאֱמַר (שמות ל יט) וְרָחֲצוּ אַהֲרֹן וּבָנָיו מִמֶּנּוּ אֶת יְדֵיהֶם וְאֶת רַגְלֵיהֶם בְּבֹאָם אֶל אֹהֶל מוֹעֵד וְגוֹ' אוֹ בְגִשְׁתָּם אֶל הַמִּזְבֵּחַ וְגוֹ'. The commandment of sanctifying the hands and the feet at the time of the service: To wash (Sefer HaMitzvot, Positive Commandments 24) the hands and the feet at all times when one enters into the sanctuary and when one comes to do the service (see Tosafot on Yoma 5b, s.v. lehavi) — and that is the commandment of the sanctification of the hands and the feet — as it is stated (Exodus 30:19-20), “And let Aharon and his sons wash their hands and feet [...] When they enter the Tent of Meeting, etc. or when they approach the altar to serve, etc.”

מִשָּׁרְשֵׁי הַמִּצְוָה. הַיְּסוֹד הַקָּבוּעַ שֶׁאָמַרְנוּ לְהַגְדִּיל כְּבוֹד הַבַּיִת וְכָל הַמְּלָאכוֹת הַנַּעֲשׂוֹת שָׁם, עַל כֵּן רָאוּי לְנַקּוֹת הַיָּדַיִם שֶׁהֵן הָעוֹשׂוֹת בַּמְּלָאכָה בְּכָל עֵת יִגְּעוּ הַכֹּהֲנִים בְּעִנְיְנֵי הַבַּיִת. וּמִזֶּה הַשֹּׁרֶשׁ אָמְרוּ זִכְרוֹנָם לִבְרָכָה (זבחים יט ב) שֶׁאֵין הַכֹּהֵן צָרִיךְ לְקַדֵּשׁ יָדָיו בֵּין עֲבוֹדָה לַעֲבוֹדָה אֶלָּא פַּעַם אַחַת בַּבֹּקֶר, וְעוֹבֵד כָּל הַיּוֹם וְכָל הַלַּיְלָה, וְהוּא שֶׁלֹּא יִישַׁן וְלֹא יַטִּיל מַיִם וְלֹא יַסִּיחַ דַּעְתּוֹ. נִרְאֶה מִכָּל זֶה שֶׁאֵין הַכַּוָּנָה בִּרְחִיצָה מִתְּחִלָּה אֶלָּא לְהַגְדָּלַת כְּבוֹד הַבַּיִת שֶׁאֲפִלּוּ הָיָה טָהוֹר וְנָקִי בִּתְחִלַּת בֹּאוֹ שָׁם צָרִיךְ לִרְחֹץ. וּמִשֶּׁהִתְחִיל בָּעֲבוֹדָה, אֵין צָרִיךְ עוֹד לִרְחִיצָה בֵּין עֲבוֹדָה לַעֲבוֹדָה זוּלָתִי בְּיוֹם הַכִּפּוּרִים לְרֹב חֻמְרוֹ שֶׁל יוֹם, לְפִי שֶׁכָּל עֵסֶק עֲבוֹדַת הַבַּיִת אָנוּ מַחְזִיקִין וְרוֹאִין בְּלִבֵּנוּ טָהוֹר, נָקִי וְקָדוֹשׁ. From the roots of the commandment is the fixed foundation that we have said [that it is] to aggrandize the glory of the [Temple] and all of the [activities] that are done there. And therefore it is fitting to clean the hands, which are the [things] that are involved in the work at all times when the priests are touching the contents of the [Temple]. And from this root, they, may their memory be blessed, said (Zevachim 19b) that the priest does not need to sanctify his hands between one service and [another] service, but rather once during the morning, and he may [then] serve the whole day and the whole night — and that is when he does not sleep and does not urinate and does not take his mind off [the service]. It appears from all of this that the intention of the washing at the beginning is only for the aggrandizement of the glory of the [Temple], since even if he was pure and clean from the beginning of his arrival there, he [still] needs to wash. And once he has started the service, he does not need to wash again between one service and [another] service, except for on Yom Kippur, due to the stringency of the day. [This is all] since we hold and see in our hearts all of the business of the service of the [Temple] as pure, clean and holy.

מִדִּינֵי הַמִּצְוָה, מָה שֶׁאָמְרוּ זִכְרוֹנָם לִבְרָכָה (זבחים כ ב) שֶׁהַיּוֹצֵא חוּץ לְחוֹמַת הָעֲזָרָה טָעוּן קִדּוּשׁ יָדַיִם, וְאִם קִדֵּשׁ יָדָיו הַיּוֹם צָרִיךְ לַחְזֹר וּלְקַדֵּשׁ לְמָחָר, אַף עַל פִּי שֶׁלֹּא יָשַׁן כָּל הַלַּיְלָה, שֶׁהַיָּדַיִם נִפְסָלוֹת בְּלִינָה. וְשֶׁמְּצַוֶּה לְכַתְּחִלָּה לִרְחֹץ בְּשַׁחֲרִית פָּנָיו יָדָיו וְרַגְלָיו, וְשֶׁמִּצְוָה לְקַדֵּשׁ בְּמֵי הַכִּיּוֹר (שם כב ב) וְאִם קִדֵּשׁ מֵאֶחָד מִכְּלֵי שָׁרֵת כָּשֵׁר דִּיעֲבַד, אֲבָל לֹא מִכְּלִי חוֹל אֲפִלּוּ דִּיעֲבַד. וְשֶׁאֵין מַכְנִיסִין יְדֵיהֶן לְתוֹכוֹ אֶלָּא שׁוֹפְכִין מִמֶּנּוּ עַל יְדֵיהֶם, וְגַם זֶה דֶּרֶךְ כָּבוֹד, וְאֵין אָנוּ מַצְרִיכִין כֵּן בְּעִנְיַן נְטִילַת יָדַיִם בְּחֻלִּין לִטֹּל מִן הַכְּלִי וְלֹא בְּתוֹכוֹ, שֶׁאַף עַל פִּי שֶׁאָנוּ מַצְרִיכִין כְּלִי לִנְטִילַת חֻלִּין, וִיסוֹד הַדָּבָר הוּא מִפְּנֵי שֶׁמָּצָאנוּ כְּלִי לִנְטִילָה בַּקֹּדֶשׁ, מִכָּל מָקוֹם בִּקְדֻשָּׁה הוּא דְּמִעֵט רַחֲמָנָא מִמֶּנּוּ וְלֹא בְּתוֹכוֹ, אֲבָל בַּחֻלִּין אֵין לָנוּ מִעוּט. וְאַף עַל פִּי שֶׁנְּטִילַת הַחֻלִּין מִשּׁוּם סֶרֶךְ הַקֳּדָשִׁים הִיא, וּכְמוֹ שֶׁאָמְרוּ זִכְרוֹנָם לִבְרָכָה (חולין קו א) מִשּׁוּם סֶרֶךְ תְּרוּמָה, מִכָּל מָקוֹם אֵין לָנוּ לְהַשְׁווֹתָם לְגַמְרֵי בְּכָל דִּינֵיהֶם, וְדַי לָנוּ לְחַיֵּב בִּנְטִילָה וּבִכְלִי בְּחֻלִּין מִשּׁוּם סֶרֶךְ זֶה, וּלְהַנִּיחַ מִעוּטוֹ דְּמִמֶּנּוּ שֶׁנֶּאֱמַר בּוֹ בִּמְקוֹמוֹ. וַאֲפִלּוּ בִּתְרוּמָה עַצְמָהּ נְטִילַת יָדַיִם בָּהּ מִדְּרַבָּנָן הוּא, כִּי מִן הַתּוֹרָה לֹא נִמְצָא טַהֲרָה רַק בְּכָל הַגּוּף בְּבַת אַחַת. וּמָה שֶׁאָמְרוּ זִכְרוֹנָם לִבְרָכָה (חולין שם) שֶׁהַנְּטִילָה מִדִּכְתִיב (ויקרא טו יא) וְיָדָיו לֹא שָׁטַף וְגוֹ', אַסְמַכְתָּא בְּעָלְמָא הוּא, כֵּן כָּתוּב בְּסֵפֶר הַמִּצְוֹת שֶׁל הָרַמְבַּ"ן זִכְרוֹנוֹ לִבְרָכָה. (עי' ספר המצוות שרש א בד"ה בתשובה השנית). From the laws of the commandment is that which they, may their memory be blessed, said (Zevachim 20b) that one who goes out of the wall of the yard requires sanctification of the hands. And that if he sanctified his hands today, he needs to go back and sanctify [them] tomorrow — even if he did not sleep the whole night — as the hands are disqualified by [passing the night]. And that the commandment is ideally to wash the face, the hands and the feet in the morning; that it is a commandment to sanctify with the water of the basin (Zevachim 22b), and that if he sanctified [his hands] from one of the serving vessels, it is fit, ex post facto — but not from a non-sacred vessel, even ex post facto. And that they do not put their hands into [the water], but we pour it over their hands — and this is also the way of honor. But we do not require this regarding the [washing] of the hands for non-sacred foods — to [wash] from a vessel and not into it. As even though we require a vessel for the [washing] for the non-sacred, and the foundation of the matter is because we found [the requirement] for a vessel by [washing] for the sanctified — nonetheless it is with the sanctified that the [Torah] excluded it, but with the non-sacred, there is no exclusion. And even though the [washing] for the non-sacred is by extension of the priestly tithe — and as they, may their memory be blessed, said (Chullin 106a), “By extension of the priestly tithe” — still we do not make them the same in all of their laws. And [so] it is enough for us to obligate [washing] and a vessel for the non-sacred — by extension of the priestly tithe — and to leave the exclusion [derived from] “from it,” that is said about it in its place. And even about the priestly tithe itself, its [washing] of the hands is rabbinic; as by Torah writ, one only finds purity for the entire body at once, and that which they, may their memory be blessed, said (Chullin 106a) that the [washing] is [derived] from that which is written (Leviticus 15:11), “and he did not wash his hands, etc.” — that is just a memory device (asmakhta). And so is it written in the Sefer HaMitzvot of Ramban, may his memory be blessed. (See Sefer HaMitzvot, Shoresh 1, s.v. beteshuvah hashenit.)

וְכֵן מָה שֶׁאָמְרוּ זִכְרוֹנָם לִבְרָכָה (זבחים כא ב) כַּמָּה מַיִם צָרִיךְ לִהְיוֹת בַּכִּיּוֹר אֵין פָּחוֹת מִשִּׁעוּר מַיִם הָרְאוּיִין לִנְטִילַת אַרְבָּעָה אֲנָשִׁים, שֶׁנֶּאֱמַר וְרָחֲצוּ אַהֲרֹן וּבָנָיו מִמֶּנּוּ אֶת יְדֵיהֶם וְאֶת רַגְלֵיהֶם וְהָיוּ אַהֲרֹן אֶלְעָזָר וְאִיתָמָר וּפִנְחָס עִמָּהֶם. וְכָל מַיִם כְּשֵׁרִין לְקִדּוּשׁ, בֵּין מֵי מַעְיָן אוֹ מֵי מִקְוֶה, וְנִפְסָלִין בְּלִינָה. וְכֵיצַד מִצְוַת קִדּוּשׁ, (זבחים יט ב) מַנִּיחַ יָדוֹ הַיְמָנִית עַל רַגְלוֹ הַיְּמָנִית, וְיָדוֹ הַשְּׂמָאלִית עַל רַגְלוֹ הַשְּׂמָאלִית, וְרוֹחֵץ עוֹמֵד וְלֹא יוֹשֵׁב, לְפִי שֶׁמִּכְּלַל הָעֲבוֹדָה הוּא קִדּוּשׁ יָדַיִם וְרַגְלַיִם, וְכָל עֲבוֹדוֹת הַמִּקְדָּשׁ מְעֻמָּד הֵן, שֶׁנֶּאֱמַר (דברים יח ה) לַעֲמֹד לְשָׁרֵת. וְכָל זֶה לְמַעֲלַת הַבַּיִת. וְיֶתֶר פְּרָטֶיהָ, מְבֹאָרִים בְּפֶרֶק שֵׁנִי מִזְּבָחִים (יט, ב). And so [too,] that which they, may their memory be blessed, said (Zevachim 21b) [about] how much water needs to be in the basin — [that it is] no less than water that is fit for the [washing] of four people — as it is stated, “And let Aharon and his sons wash their hands and their feet.” And they were Aharon and Elazar and Itamar, and Pinchas was with them. And that all water is fit for sanctification — whether the water from a spring or the water of a pool (mikveh) — and they are disqualified by [passing the night]. And how is the commandment of the sanctification (Zevachim 19b) — that he places his right hand on his right foot and his left hand on his left foot and washes standing up and not sitting. As the sanctification of the hands and feet is included in the service, and all of the services of the Temple are [done while] standing up — as it is stated (Deuteronomy 18:5), “to stand and to serve.” And all of this is for the loftiness of the [Temple]. And the rest of its details are elucidated in the second chapter of Zevachim.

וְנוֹהֶגֶת בִּזְמַן הַבַּיִת בְּזִכְרֵי כְּהֻנָּה בִּלְבַד. וְהָעוֹבֵר עָלֶיהָ וְלֹא קִדֵּשׁ יָדָיו וְרַגְלָיו שַׁחֲרִית, אוֹ שֶׁיָּצָא מִן הַמִּקְדָּשׁ וְהֵסִיחַ דַּעְתּוֹ וְחָזַר וְעָבַד בְּלֹא קִדּוּשׁ חַיָּב מִיתָה בִּידֵי שָׁמַיִם, וַעֲבוֹדָתוֹ פְּסוּלָה, בֵּין כֹּהֵן גָּדוֹל אוֹ הֶדְיוֹט. And it is practiced at the time of the Temple by the males of the priesthood alone. And one who transgresses it and does not sanctify his hands and his feet in the morning, or if he goes out from the Temple and removes his thoughts and comes back and serves without sanctification, is liable for death at the hands of Heaven — and his service is disqualified — whether he is a high priest or a regular priest.