Genesis 35:21-23 New Century Version (NCV)

21. Then Israel continued his journey and camped just south of Migdal Eder.

22. While Israel was there, Reuben had sexual relations with Israel’s slave woman Bilhah, and Israel heard about it.Jacob had twelve sons.

23. He had six sons by his wife Leah: Reuben, his first son, then Simeon, Levi, Judah, Issachar, and Zebulun.

Genesis 35