Genesis 35:22-24

New Revised Standard Version, Anglicised

²² While Israel lived in that land, Reuben went and lay with Bilhah his father’s concubine; and Israel heard of it.

Now the sons of Jacob were twelve. ²³ The sons of Leah: Reuben (Jacob’s firstborn), Simeon, Levi, Judah, Issachar, and Zebulun. ²⁴ The sons of Rachel: Joseph and Benjamin.