The Mark of Cain and the Power of Repentance

"Therefore whoever slays Cain." Rabbi Yehudah and Rabbi Nehemiah differed. Rabbi Yehudah says: The beasts, the wild animals, and the birds gathered to demand the blood of Abel. The Holy One, blessed be He, said to them, "Therefore I say, whoever slays Cain shall be slain." Rav Levi said: The primeval serpent came to demand judgment for Abel. The Holy One, blessed be He, said to him, "Therefore I say, whoever slays Cain shall be slain." Cain's judgment is unlike the judgment of murderers: Cain killed but had no one from whom to learn; from here onward, whoever slays Cain shall be slain. "And the LORD set a sign for Cain." Rabbi Yehudah and Rabbi Nehemiah differed. Rabbi Yehudah says: He caused the orb of the sun to shine for him. Rav Nehemiah said: For that wicked one the Holy One, blessed be He, would make the sun's orb shine? Rather, it teaches that He made leprosy break out upon him, as you say, (Exodus 4:8) "and they will believe the voice of the latter sign." Rav said: He gave him a dog. Another interpretation: He made a horn grow upon him. Another interpretation: He made him a sign for murderers. Another interpretation: He made him a sign for the penitent. And some say: He suspended him in a loose state, and the Flood came and washed him away. (Genesis 4:16) "And Cain went out from before the LORD." From where did he go out? He cast the matter behind him and went out like one who deceives the Higher Mind. Another interpretation: He went out like one who is cunning and deceitful toward his Creator. Another interpretation: He went out rejoicing, as you say, (Exodus 4:14) "behold, he comes out to meet you." Adam met him and said, "What was done in your judgment?" He said, "I repented and reached a settlement." Adam began to strike his face and said, "Such is the power of repentance, and I did not know!" Immediately Adam arose and said, (Psalms 92:1-2) "A psalm, a song for the Sabbath day. It is good to give thanks to the LORD." Rav Levi said: Adam said this psalm, and it was forgotten in his generation, and Moses came and restored it in his own name, "A psalm, a song for the Sabbath day, it is good to give thanks." "Hear my voice." Because they were withdrawing from him from marital relations, since he had killed Cain and Tubal-cain. For Lamech was blind, and Tubal-cain saw Cain and he appeared to him like a beast, and he told his father to draw the bow, and he killed him. And once he knew it was Cain his ancestor, he struck palm against palm and clapped his son between them and killed him. And his wives withdrew from him, and he was appeasing them: "And was it a man whom I killed, and did I wound him deliberately, that the wound should be called by my name? And a child whom I killed for my bruising, was killed; surely I was unintentional. If Cain who killed deliberately was given a respite of seven generations, I who killed unintentionally, how much more so."