Jerusalem Talmud Yoma 1:8

משנה: בְּכָל־יוֹם תּוֹרְמִין אֶת הַמִּזְבֵּחַ מִקְּרוֹת הַגֶּבֶר אוֹ בְסָמוּךְ לוֹ מִלְּפָנָיו אוֹ מִלְּאַחֲרָיו. וּבְיוֹם הַכִּפּוּרִים מֵחֲצוֹת. וּבָֽרְגָלִים מֵאַשְׁמוֹרֶת הָרִאשׁוֹנָה. לֹא הָֽיְתָה קְרוֹת הַגֶּבֶר מַגַּעַת עַד שֶׁהָֽיְתָה עֲזָרָה מְלֵיאָה מִיִּשְׂרָאֵל׃ MISHNAH: Every day one removes ashes from the altar²³⁷The removal of the ashes from the previous day is the required action before the service of the new day may start; Lev.6:1–6. about at the call of the cock, before it or after it. But on the Day of Atonement at midnight²³⁸To let the High Priest start the office of the day at the earliest possible moment., and on holidays after the first watch²³⁹The end of the first third of the night. On holidays not only were there many additional public offerings but also a very great number of private holiday offerings' taking up the entire day.. The cock did not crow²⁴⁰On holidays and the Day of Atonement. before the Courtyard was full of Israel.

הלכה: אָמַר רִבִּי מָנָא. לֹא מִסְתַּבְּרָא. דְּלֹא יוֹם הַכִּפּוּרִים מֵאַשְׁמוֹרֶת הָרִאשׁוֹנָה. וּבָֽרְגָלִים מֵחֲצוֹת. שֶׁלֹּא יָבוֹאוּ לִידֵי צִמָּאוֹן. אָמַר רִבִּי יוֹחָנָן. תְּרוּמַת הַדֶּשֶׁן תְּחִילַּת עֲבוֹדָה שֶׁלְמָחָר הִיא. וְצָרִיךְ לְקַדֵּשׁ יָדָיו וְרַגְלָיו מִן הַכִּיּוֹר המְשׁוּקָּע בַמַּיִם. HALAKHAH: Rebbi Mana said, would it not be understandable if on the day of Atonement it were after the first watch and on holidays from midnight, that they²⁴¹Everybody involved in the service of the fast day. R. Mana’s opinion is not mentioned in the Babli. should not become thirsty? Rebbi Joḥanan said, the removal of ashes is the start of the service of the next say and one had to sanctify his hands and feet from the basin which was immersed in water²⁴²Washing hands and feet before any sacral act is an absolute requirement, Ex.30:17–21. But the water used on one day would become unusable the next day unless it is at least 40 seˋah, the minimum volume of a miqweh whose water always is pure. Therefore the wash basin of the priests has to be immersed in a large miqweh during the night and can be lifted for easy use only at dawn. For the removal of ashes on the special days, hands and feet have to be washed in the miqweh. In the interpretation of the Babli Zevaḥim 21b, R. Joḥanan holds that since the removal of the ashes is the start of the service of the next day, the Cohen washing for the removal does not have to wash again for the morning service..