וַיִּקְרְא֨וּ אֶל־יְהוָ֜ה וַיֹּאמְר֗וּ אָנָּ֤ה יְהוָה֙ אַל־נָ֣א נֹאבְדָ֗ה בְּנֶ֙פֶשׁ֙ הָאִ֣ישׁ הַזֶּ֔ה וְאַל־תִּתֵּ֥ן עָלֵ֖ינוּ דָּ֣ם נָקִ֑יא כִּֽי־אַתָּ֣ה יְהוָ֔ה כַּאֲשֶׁ֥ר חָפַ֖צְתָּ עָשִֽׂיתָ׃
Lalu mereka berseru kepada Yang Mahakekal dan berkata, “Ya Yang Mahakekal, kami mohon, janganlah kiranya kami binasa karena nyawa orang ini, dan janganlah Engkau tanggungkan kepada kami darah orang yang tidak bersalah, sebab Engkau, ya Yang Mahakekal, telah berbuat sesuai dengan kehendak-Mu.”
Shenei Luchot HaBerit
I have found a similar interpretation by the Rekanati who writes as follows: "The plain meaning of the prayer in 21,8: 'do not burden the people of Israel with the guilt of shedding innocent blood' is undoubtedly the spilling of blood of the innocent. We must ask, however, why there is a need to pray to G–d not to burden us with a guilt we have not been guilty of? Who could imagine that G–d would punish without due process of law? Was this not precisely the response of Avimelech to G–d when he knew that he had not actually raped Sarah (Genesis 20,5)? He claimed that Sarah had misled him! King David in Psalms 7,5 said: "If I have dealt evil to my ally, etc." He defended himself against G–d not considering him worthy of intervention because of a sin he might have committed quite by accident. A similar passage is found in the Book of Jonah when the sailors about to go down with their ship reluctantly agreed to save themselves by throwing Jonah overboard (Jonah 1,14).