“The Lord said to him: Therefore, anyone who kills Cain, vengeance will be taken on him sevenfold. The Lord placed a sign for Cain, so that anyone who would find him would not smite him” (Genesis 4:15). “The Lord said to him: Therefore, anyone who kills Cain” – Rabbi Yehuda and Rabbi Neḥemya, Rabbi Yehuda says: The animals, the beasts, and the birds all gathered to demand justice for Abel’s blood.
He [God] said to them: “Therefore”50Because of your actions. I am saying: “Anyone who kills Cain” will be killed. Rabbi Levi said: The primeval serpent came to demand justice for Abel. The Holy One blessed be He said to it: “Therefore” I am saying: “Anyone who kills Cain” will be killed.
Rabbi Neḥemya said: Cain’s sentence was unlike the sentence of murderers,51He was not sentenced to death like other murderers. as he had no one from whom he could learn. From here on, “anyone who kills Cain” will be killed. “The Lord placed a sign for Cain” – Rabbi Yehuda and Rabbi Neḥemya, Rabbi Yehuda said: “He caused the orb of the sun to shine for him.52Regarding the creation of the lights, including the sun, it is written: “They will be as signs” (Genesis 1:14).
Rabbi Neḥemya said: Would the Holy One blessed be He cause the orb of the sun to shine on behalf of that wicked one? Rather, it teaches that he caused leprosy to glow on him, just as you say: “It will be that if they do not believe you, and do not heed the voice of [the first] sign, [they will believe the voice of the latter sign]” (Exodus 4:8).53The latter sign was leprosy, indicating that leprosy is called a sign.
Rav said: He gave him [Cain] a dog. Abba Yosei ben Kesari said: He caused a horn to sprout forth for him.54Both the dog and the horn were intended to ensure “that anyone who would find him would not smite him.” Rav said: He rendered him a “sign” for murderers.55To warn others not to follow Cain’s practice. Rabbi Ḥanin said: He rendered him a “sign” for penitents.56For others to follow his practice.
Cain confessed his sin (see section 11). Rabbi Levi said in the name of Rabbi Shimon ben Lakish: His sentence was pending until the Flood came and washed him away, as it is stated: “He obliterated all existence [haykum] that was on the face of the earth” (Genesis 7:23), just as it says: “Cain rose [vayakam]” (Genesis 4:8).