Genesis 48:3-6

3Jacob said to Joseph, “God Almighty appeared to me at Luz in the land of Canaan, and there he blessed me

4and said to me, ‘I am going to make you fruitful and increase your numbers. I will make you a community of peoples, and I will give this land as an everlasting possession to your descendants after you.’

5“Now then, your two sons born to you in Egypt before I came to you here will be reckoned as mine; Ephraim and Manasseh will be mine, just as Reuben and Simeon are mine.

6Any children born to you after them will be yours; in the territory they inherit they will be reckoned under the names of their brothers.