כַּפֵּר֩ לְעַמְּךָ֨ יִשְׂרָאֵ֤ל אֲשֶׁר־פָּדִ֙יתָ֙ יְהוָ֔ה וְאַל־תִּתֵּן֙ דָּ֣ם נָקִ֔י בְּקֶ֖רֶב עַמְּךָ֣ יִשְׂרָאֵ֑ל וְנִכַּפֵּ֥ר לָהֶ֖ם הַדָּֽם׃
פֿאַרגיב דײַן פֿאָלק ישׂראל, װאָס דו, גאָט, האָסט אױסגעלײזט, און לאָז ניט אומשולדיק פֿאַרגאָסן בלוט צװישן דײַן פֿאָלק ישׂראל, און זײ זאָל פֿאַרגעבן װערן דאָס בלוט.
Rashi
ונכפר להם הדם AND THE BLOOD SHALL BE PARDONED THEM — Scripture announces to them that when they have done this (the ceremony prescribed) their sin will be forgiven (Sotah 46a).
Chizkuni
כפר לעמך ישראל, “forgive Your people Israel!” They ask forgiveness for not having provided adequate security on the roads leading to their town so that this kind of murder could not have occurred and the perpetrator escaping with impunity. (Ibn Ezra)...
Ibn Ezra
forgive your people For we were negligent, and we did not guard the dangerous highways.