Genesis 19:32

19:32 Come, let’s make our father drunk with wine so we can have sexual relations with him and preserve our family line through our father.”

Genesis 30:3

30:3 She replied, “Here is my servant Bilhah! Have sexual relations with her so that she can bear children for me and I can have a family through her.”

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: