Genesis 35:21-23 Lexham English Bible (LEB)
21 And Israel journeyed on and pitched his tent beyond the tower of Eder.[a] 22 And while Israel was living in that land Reuben went and had sexual relations with Bilhah, his father’s concubine. And Israel heard about it.
The Twelve Sons of Jacob
Now the sons of Jacob were twelve. 23 The sons of Leah: The firstborn of Jacob was Reuben. Then Simeon, Levi, Judah, Issachar, and Zebulun.