Mishnayos Pesachim Perek 5 Mishnah 5

The Paschal lamb was slaughtered in three groups, meaning those bringing the offering were divided into three separate sets, as it is stated: “And the whole assembly of the congregation of Israel shall slaughter it in the afternoon” (Exodus 12:6). The verse is interpreted as referring to three groups: Assembly, congregation, and Israel. The procedure for sacrificing the offering was as follows: The first group of people sacrificing the offering entered, and when the Temple courtyard became filled with them they closed the doors of the Temple courtyard. They sounded uninterrupted, broken, and uninterrupted trumpet blasts, as was done while sacrificing any offering. The priests stood in rows from the place of slaughter to the altar, and in their hands they held bowls [bezikhin] of silver and bowls of gold in order to receive the blood of the offerings. There was a row entirely composed of priests holding silver bowls, and a row entirely composed of priests holding gold bowls, as the gold and silver bowls were not mixed in the same row. The bowls did not have flat bases that would allow them to be put down, out of concern that perhaps the priests would set them down and forget about them and in the meantime the blood would congeal and become disqualified for sprinkling on the altar.

הַפֶּסַח נִשְׁחָט בְּשָׁלֹשׁ כִּתּוֹת, שֶׁנֶּאֱמַר וְשָׁחֲטוּ אֹתוֹ כֹּל קְהַל עֲדַת יִשְׂרָאֵל, (שמות יב) קָהָל וְעֵדָה וְיִשְׂרָאֵל. נִכְנְסָה כַת הָרִאשׁוֹנָה, נִתְמַלֵּאת הָעֲזָרָה, נָעֲלוּ דַלְתוֹת הָעֲזָרָה. תָּקְעוּ, הֵרִיעוּ וְתָקָעוּ. הַכֹּהֲנִים עוֹמְדִים שׁוּרוֹת שׁוּרוֹת, וּבִידֵיהֶם בָּזִיכֵי כֶסֶף וּבָזִיכֵי זָהָב. שׁוּרָה שֶׁכֻּלָּהּ כֶּסֶף כֶּסֶף, וְשׁוּרָה שֶׁכֻּלָּהּ זָהָב זָהָב. לֹא הָיוּ מְעֹרָבִין. וְלֹא הָיוּ לַבָּזִיכִין שׁוּלַיִם, שֶׁמָּא יַנִּיחוּם וְיִקְרַשׁ הַדָּם: