Genesis 35:22-26

While Israel was there, Reuben had sexual relations with Israel’s slave woman Bilhah, and Israel heard about it. Jacob had twelve sons. He had six sons by his wife Leah: Reuben, his first son, then Simeon, Levi, Judah, Issachar, and Zebulun. He had two sons by his wife Rachel: Joseph and Benjamin. He had two sons by Rachel’s slave girl Bilhah: Dan and Naphtali. And he had two sons by Leah’s slave girl Zilpah: Gad and Asher. These are Jacob’s sons who were born in Northwest Mesopotamia.