Genesis 48:5, 13-14, 18-20

And now your two sons, Ephraim and Manasseh, who were born to you in the land of Egypt before I came to you in Egypt, are mine; as Reuben and Simeon, they shall be mine.

And Joseph took them both, Ephraim with his right hand toward Israel’s left hand, and Manasseh with his left hand toward Israel’s right hand, and brought them near him. Then Israel stretched out his right hand and laid it on Ephraim’s head, who was the younger, and his left hand on Manasseh’s head, guiding his hands knowingly, for Manasseh was the firstborn.

And Joseph said to his father, “Not so, my father, for this one is the firstborn; put your right hand on his head.” But his father refused and said, “I know, my son, I know. He also shall become a people, and he also shall be great; but truly his younger brother shall be greater than he, and his descendants shall become a multitude of nations.” So he blessed them that day, saying, “By you Israel will bless, saying, ‘May God make you as Ephraim and as Manasseh!’ ” And thus he set Ephraim before Manasseh.