Genesis 48:17-19

17When Joseph saw that his father laid his right hand on the head of Ephraim, it was evil in his eyes; and he took hold of his father's hand to remove it from Ephraim's head to Manasseh's head.

18And Joseph said to his father, Not so, my father, for this is the firstborn: put thy right hand on his head.

19But his father refused and said, I know, my son, I know: he also will become a people, and he also will be great; but truly his younger brother will be greater than he; and his seed will become the fulness of nations.