Kabbalah Library

230) “And every firstborn of an ass you shall redeem with a lamb.” It is a commandment to redeem the firstborn of an ass, and to decapitate the firstborn of an ass, if it is not redeemed, as it is written, “But if you do not redeem it, then you shall behead it.” This is the meaning of the evil inclination being able to repent and to later return to being good inclination, as it is written, “I will make him a helpmate against him.” If he is rewarded, “help”; if not rewarded, “against him.”

This is because it was written about these forms, a lamb and an ass, “Every firstborn of an ass you shall redeem with a lamb,” meaning that if he is rewarded with repenting, although he is an ass, ignorant, he will be redeemed from the exile with a lamb, which is as it is written, “a lamb is the disperse of Israel.” And if he does not repent, “You shall behead him,” since he makes himself a stiff-necked people, and they are destined to be blotted out from the book of life. It is written about them, “Whoever has sinned against Me, I will blot him out of My book.”