Leah the Hated Wife and Reuben the Firstborn's Double Portion

[Another interpretation of "And the LORD saw that Leah was hated."] This is what the verse says (Deuteronomy 21:15): "If a man have two wives" — this is Jacob, as it is said, "And Jacob was a plain man" (Genesis 25:27). "Two wives" (Deuteronomy 21:15) — Leah and Rachel. "The one beloved" (ibid.) — this is Rachel, as it is said, "And he loved also Rachel" (Genesis 29:30). "And the one hated" (Deuteronomy 21:15) — this is Leah, as it is said, "And the LORD saw that Leah was hated" (Genesis 29:31). "And they have borne him children, both the beloved and the hated" (Deuteronomy 21:15) — both of them bore for him. And what Leah raised up, Rachel raised up: Leah raised up kings, and likewise Rachel [raised up kings; Leah raised up prophets, and likewise Rachel raised up prophets]; Leah raised up judges, and likewise Rachel. Therefore it is said, "And they have borne him children" (Deuteronomy 21:15). "And it shall be, in the day that he causeth his sons to inherit" (Deuteronomy 21:16) — at the hour when he came to depart from the world, "And Jacob called unto his sons" (Genesis 49:1). "He may not make the son of the beloved the firstborn" (Deuteronomy 21:16) — Joseph. Why? "But he shall acknowledge the firstborn, the son of the hated" (Deuteronomy 21:17) — this is Reuben, as it is said, "Reuben, thou art my firstborn" (Genesis 49:3). Even though he said in his disgrace, "Unstable as water, thou shalt not excel" (Genesis 49:4) — what is "he went up to my couch" (ibid.)? When Moses comes, of whom it is written, "And Moses went up unto God" (Exodus 19:3), he will redeem him. And when Moses arose, he sought mercy for him, as it is said, "Let Reuben live" (Deuteronomy 33:6). The Holy One, blessed be He, said, "and not die" — he is found receiving a pardon from the mouth of both of them, as it is said, "But he shall acknowledge the firstborn, the son of the hated, by giving him a double portion" (Deuteronomy 21:17). "Let Reuben live, and not die" (Deuteronomy 33:6) — let Reuben live in this world, and not die in the world to come. And why? "For he is the firstfruits of his strength" [and it is written, "my might, and the firstfruits of my strength"] (Genesis 49:3).