Genesis 25:16

25:16 These are the sons of Ishmael, and these are their names by their settlements and their camps – twelve princes according to their clans.

Genesis 35:22

35:22 While Israel was living in that land, Reuben had sexual relations with Bilhah, his father’s concubine, and Israel heard about it.

Jacob had twelve sons:

Genesis 49:28

49:28 These are the twelve tribes of Israel. This is what their father said to them when he blessed them. He gave each of them an appropriate blessing.