Genesis 49:1-2, 28

And Jacob called unto his sons, and said: Gather yourselves together, that I may tell you that which shall befall you in the latter days. Assemble yourselves, and hear, ye sons of Jacob; And hearken unto Israel your father.

All these are the twelve tribes of Israel: and this is it that their father spake unto them and blessed them; every one according to his blessing he blessed them.