אָ֭דָם עָשֻׁ֣ק בְּדַם־נָפֶשׁ עַד־בּ֥וֹר יָ֝נ֗וּס אַל־יִתְמְכוּ־בֽוֹ׃
אַ מענטש װאָס האָט אױף זיך דאָס בלוט פֿון אַ נפֿש, װעט לױפֿן ביזן גרוב, מע װעט אים ניט בײַשטײן.
Tosafot Yom Tov
AND WHOEVER BRINGS THE PEOPLE TO SIN WILL NOT BE GIVEN THE MEANS TO REPENT. Rav: in order that he shouldn’t end up in the Garden of Eden while his students are in Gehinnom. This is from that same passage in the Talmud, where it is derived from the verse “let a man crushed [by guilt] over the bloodshed [lit. blood of a soul] flee to a pit and let none support him” (Proverbs 28:17). Although the verse says “blood of a soul”, even one soul, the mishna says “whoever brings the people to sin” because G-d has a greater tendency to reward than to punish, and even so only one who brings “the people” to do good is saved from sin by his deed—it is all the more true, then, that G-d would only punish one who brings the people to sin.
Rashbam
ואם תלכו עמי קרי, Menachem interprets the word קרי as related to Proverbs 28,17 הוקר רגלך, “restrain your foot.” This is nonsense. The word הוקר in Proverbs is derived from a group of verbs known as פ'ה, first root letter being the letter ה, as in Genesis 47,6 הושב את אביך, a transitive mode of the root ישב, meaning: “settle your father, etc.” The word קרי is derived from the root קרה as in Numbers 23,15, meaning: “if you will walk with Me as if your fate is subject to coincidences, totally arbitrary happenings, not subject to providence, as a person who walks haphazardly, not following a definitive direction.”
Rabbeinu Bahya
ולא תקחו כופר לנפש רוצח, “and you must not accept a ransom payment in exchange of the life of the murderer.” The Torah tells us here that no amount of money is adequate to atone for the death of a Jew; hence a ransom payment is out of the question. The guilt of murdering someone is the greatest sin between man and his fellow man. Solomon told us in Proverbs 28,17: “a man burdened with blood guilt will flee to a pit; let no one help him.” We may learn a lesson from Achav, King of Israel. When the prophet makes comparisons between the levels of guilt of different kings we are told in Kings I 21,25 concerning a very evil king, “there was never one like Achav who committed himself to doing what was displeasing to the Lord, at the instigation of his wife Izzevel.” When Achav’s sins were measured and his merits were weighed against them, the decisive sin held against him was that he had framed Navot and had him executed. This is why we read in Kings I 22,21: “the spirit (of the deceased Navot) came forward before the Lord and said: “I will entice him.” “How?, the Lord asked him.” And he replied: “I will go out and be a lying spirit in the mouth of all his prophets.” Then He (G’d) said: “you will entice and you will prevail. Go out and do it.” (Compare Sanhedrin 102). The story is an illustration that although Achav had not even killed with his own hands and could have pointed to the court which convicted Navot as guilty as responsible for his death, G’d considered the deed as his. How much more severely must someone be viewed who killed with his own hands.