Genesis 41:51

41:51 Joseph named the firstborn Manasseh, saying, “Certainly God has made me forget all my trouble and all my father’s house.”

Genesis 46:20

46:20 Manasseh and Ephraim were born to Joseph in the land of Egypt. Asenath daughter of Potiphera, priest of On, bore them to him.

Genesis 48:18

48:18 Joseph said to his father, “Not so, my father, for this is the firstborn. Put your right hand on his head.”

Deuteronomy 21:17

21:17 Rather, he must acknowledge the son of the less loved wife as firstborn and give him the double portion of all he has, for that son is the beginning of his father’s procreative power – to him should go the right of the firstborn.