458) “And the Lord set a token for Cain.” He placed on him one of the twenty-two letters of the Torah, the letter Vav, to protect him, since the letter Vav is a token of the covenant with which he was rewarded after he had repented and took upon himself the keeping of the covenant.

Rabbi Yehuda said, “And it came to pass, when they were in the field, that Cain rose up against Abel, his brother, and killed him.” “In the field” means a woman. Hence, Cain killed Abel because of a woman, since from the side of a woman, the left side, he inherited the power of murdering, the side of SAM, which caused death to the entire world by seducing Adam and Eve with the tree of knowledge. Cain envied Abel for the Nukva, the additional Nukva that Abel had.

The meaning of the soul of Cain and Abel is that Abel is MI and Cain is ELEH. It is known that MI extend from upper AVI, and ELEH extend from YESHSUT, which are two females in AVI, lock and key. But they emanated to YESHSUT ‎only in the key, who is one Nukva. It follows that Cain, who was extended in the form of ELEH, had only one Nukva, the key. But Abel had two females, of the lock and of the key. This is why Cain envied Abel for his additional Nukva, the Nukva of the lock.

Rabbi Hiya said, “But we see the reason for Abel’s killing, as it is written, ‘But to Cain and to his offering, He did not respond, and Cain became very angry,’ for his offering was not accepted, and not because of a Nukva, as Rabbi Yehuda said.” Rabbi Yehuda told him, “So it is that Cain was angered by his offering not being accepted, and everything was before him when he killed Abel, meaning the envy for the additional Nukva, too.”

459) “And the Lord said unto Cain ... If you do well, moreover; and if you do not do well, sin crouches at the door.” The Creator told him, “If you improve your works then moreover.” “Moreover” [which can also mean “strength” in Hebrew] is as it is written of Reuben, Jacob’s first born, “Reuben, you are my firstborn, my might, and the first of my strength,” since the firstborn always has merit and advantage in everything, and depends on his works. This is why the Creator said to him, “If you do well.” “And if you do not do well, sin crouches at the door.”