"Our hands have not spilled": Now would it enter our minds that the elders of beth-din are spillers of blood! (The intent is:) He (the slain one) was not "in our hands" and dismissed without a meal; and we did not see him, (corresponding to "our eyes have not seen") and let him go without an escort.
These are the dead, whereby we are taught that the dead, too, require atonement, and that this atonement atones until the exodus from Egypt, and that the spiller of blood sins (retroactively) until the exodus from Egypt.
"which You have redeemed": It is to this end that You redeemed us — that there be no spillers of blood among us. Variantly: It is to this end that You redeemed us — that if we sinned You would make atonement for us. "and the blood will be atoned unto them":
(דברים כא ז) וְעָנוּ וְאָמְרוּ, בִּלְשׁוֹן הַקֹּדֶשׁ.
(Devarim 21:7) "And they shall answer and say": in the holy tongue.
יָדֵינוּ לֹא שָׁפְכָה, וְכִי עָלָת עַל לִבֵּנוּ שֶׁזִּקְנֵי בֵּית דִּין שׁוֹפְכֵי דָמִים הֵם? אֶלָּא שֶׁלֹּא בָא לְיָדֵינוּ וּפְטַרְנוּהוּ בְּלֹא מְזוֹנוֹת, וְלֹא רְאִינוּהוּ וְהִנַּחְנוּהוּ בְּלֹא לְוָיָה.
"Our hands have not spilled": Now would it enter our minds that the elders of beth-din are spillers of blood! (The intent is:) He (the slain one) was not "in our hands" and dismissed without a meal; and we did not see him, (corresponding to "our eyes have not seen") and let him go without an escort.
(דברים כא ח) הַכֹּהֲנִים אוֹמְרִים: כַּפֵּר לְעַמְּךָ יִשְׂרָאֵל.
And the Cohanim say (Ibid. 8) "Forgive Your people, Israel, which You have redeemed, O L-rd."
כְּשֶׁהוּא אוֹמֵר אֲשֶׁר פָּדִיתָ ה׳, מְלַמֵּד שֶׁכַּפָּרָה זוֹ מְכַפֶּרֶת עַל יוֹצְאֵי מִצְרַיִם.
"which You have redeemed ": This teaches that this atonement atones for those that left Egypt.
כַּפֵּר לְעַמְּךָ – אֵלּוּ הַחַיִּים;
"Forgive Your people": These are the living;
אֲשֶׁר פָּדִיתָ – אֵלּוּ הַמֵּתִים, מַגִּיד שֶׁהַמֵּתִים צְרִיכִים כַּפָּרָה. נִמְצִינוּ לְמֵדִים שֶׁשּׁוֹפֵךְ דָּמִים חוֹטֵא עַד יוֹצְאֵי מִצְרַיִם.
These are the dead, whereby we are taught that the dead, too, require atonement, and that this atonement atones until the exodus from Egypt, and that the spiller of blood sins (retroactively) until the exodus from Egypt.
אֲשֶׁר פָּדִיתָ – עַל מְנָת כֵּן פְּדִיתָנוּ, שֶׁלֹּא יִהְיוּ בֵּינֵינוּ שׁוֹפְכֵי דָמִים. דָּבָר אַחֵר: עַל מְנָת כֵּן פְּדִיתָנוּ, שֶׁאִם נֶחֱטָא – אַתָּה מְכַפֵּר עָלֵינוּ.
"which You have redeemed": It is to this end that You redeemed us — that there be no spillers of blood among us. Variantly: It is to this end that You redeemed us — that if we sinned You would make atonement for us. "and the blood will be atoned unto them":
וְרוּחַ הַקֹּדֶשׁ אוֹמֶרֶת: כָּל זְמַן שֶׁתַּעֲשׂוּ כָּכָה – הַדָּם מִתְכַּפֵּר לָכֶם.
The Holy Spirit says this: "If you do as prescribed herein, the blood will be atoned unto you."
(דברים כא ט) וְאַתָּה תְּבַעֵר – בַּעֵר עוֹשֵׂי הָרָעוֹת מִיִּשְׂרָאֵל!
(Ibid. 9) "And you shall remove the innocent blood from your midst.": Remove the doers of evil from Israel.