Mishnayos Sotah Perek 9 Mishnah 6

The Elders of that city would then wash their hands in water in the place of the breaking of the neck of the heifer, and they would recite: “Our hands did not spill this blood, nor did our eyes see” (Deuteronomy 21:7). The mishna explains: But did it enter our minds that the Elders of the court are spillers of blood, that they must make such a declaration? Rather, they mean to declare that the victim did not come to us and then we let him take his leave without food, and we did not see him and then leave him alone to depart without accompaniment. They therefore attest that they took care of all his needs and are not responsible for his death even indirectly. And the priests recite: “Forgive, Lord, Your people Israel, whom You have redeemed, and suffer not innocent blood to remain in the midst of Your people Israel” (Deuteronomy 21:8). They did not have to recite the conclusion of the verse: “And the blood shall be forgiven for them,” as this is not part of the priests’ statement, but rather the Divine Spirit informs them: When you shall do so, the blood is forgiven for you.

זִקְנֵי אוֹתָהּ הָעִיר רוֹחֲצִין אֶת יְדֵיהֶן בַּמַּיִם בִּמְקוֹם עֲרִיפָה שֶׁל עֶגְלָה, וְאוֹמְרִים, (שם) יָדֵינוּ לֹא שָׁפְכֻה אֶת הַדָּם הַזֶּה וְעֵינֵינוּ לֹא רָאוּ. וְכִי עַל דַּעְתֵּנוּ עָלְתָה, שֶׁזִּקְנֵי בֵית דִּין שׁוֹפְכֵי דָמִים הֵן, אֶלָּא שֶׁלֹּא בָא לְיָדֵינוּ וּפְטַרְנוּהוּ בְלֹא מָזוֹן, וְלֹא רְאִינוּהוּ וְהִנַּחְנוּהוּ בְלֹא לְוָיָה. וְהַכֹּהֲנִים אוֹמְרִים, (שם) כַּפֵּר לְעַמְּךָ יִשְׂרָאֵל אֲשֶׁר פָּדִיתָ ה' וְאַל תִּתֵּן דָּם נָקִי בְּקֶרֶב עַמְּךָ יִשְׂרָאֵל. לֹא הָיוּ צְרִיכִים לוֹמַר (שם) וְנִכַּפֵּר לָהֶם הַדָּם, אֶלָּא רוּחַ הַקֹּדֶשׁ מְבַשַּׂרְתָּן, אֵימָתַי שֶׁתַּעֲשׂוּ כָּכָה, הַדָּם מִתְכַּפֵּר לָהֶם: