Genesis 48:3-6

3And Jacob said unto Joseph, God Almighty appeared unto me at Luz in the land of Canaan, and blessed me, 4And said unto me, Behold, I will make thee fruitful, and multiply thee, and I will make of thee a multitude of people; and will give this land to thy seed after thee for an everlasting possession.

5And now thy two sons, Ephraim and Manasseh, which were born unto thee in the land of Egypt before I came unto thee into Egypt, are mine; as Reuben and Simeon, they shall be mine. 6And thy issue, which thou begettest after them, shall be thine, and shall be called after the name of their brethren in their inheritance.