Genesis 48:17-19

17Joseph saw that his father had put his right hand on Ephraim's head. This made Joseph upset. So he took hold of his father's right hand. He moved it from Ephraim's head on to Manasseh's head.

18Joseph said to Jacob, ‘No, my father. This boy is the firstborn son. Put your right hand on his head.’

19But Jacob refused to change. He said, ‘I know, my son. I know what I am doing. Manasseh will also have many descendants who become a great nation. But his younger brother, Ephraim, will become even greater. Ephraim's descendants will become many great nations.’