Genesis 35:22

35:22 While Israel was living in that land, Reuben had sexual relations with Bilhah, his father’s concubine, and Israel heard about it.

Jacob had twelve sons:

Genesis 42:22

42:22 Reuben said to them, “Didn’t I say to you, ‘Don’t sin against the boy,’ but you wouldn’t listen? So now we must pay for shedding his blood!”