Genesis 35:22
22 While Israel lived in that land, Reuben went and alay with Bilhah his father’s concubine. And Israel heard of it.
Now the sons of Jacob were twelve.
Genesis 49:4
4 Unstable as water, you shall not have preeminence,
because you awent up to your father’s bed;
then you defiled it—he went up to my couch!