Genesis 48:3-6

3Then Jacob said to Joseph, “God Almighty appeared to me at Luz (Bethel) in the land of Canaan and blessed me,

4and said to me, ‘Behold, I will make you fruitful and numerous, and I will make you a great company of people, and will give this land to your descendants after you as an everlasting possession.’

5Now 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; Ephraim and Manasseh shall be mine [that is, adopted as my heirs and sons as surely], as Reuben and Simeon are my sons.

6But other sons who were born to you after them shall be your own; they shall be called by the names of their [two] brothers in their inheritance.