Genesis 35:22-23 ▼

22 While Israel was living in that land, Reuben [his eldest son] went and lay with Bilhah his father’s concubine, and Israel heard about it. Now Jacob had twelve sons—

23 The sons of Leah: Reuben, Jacob’s firstborn, then Simeon, Levi, Judah, Issachar, and Zebulun;