Genesis 29:29

29:29 (Laban gave his female servant Bilhah to his daughter Rachel to be her servant.)

Genesis 30:3-8

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.”

30:4 So Rachel gave him her servant Bilhah as a wife, and Jacob had marital relations with her. 30:5 Bilhah became pregnant and gave Jacob a son. 30:6 Then Rachel said, “God has vindicated me. He has responded to my prayer and given me a son.” That is why she named him Dan.

30:7 Bilhah, Rachel’s servant, became pregnant again and gave Jacob another son. 30:8 Then Rachel said, “I have fought a desperate struggle with my sister, but I have won.” So she named him Naphtali.

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 35:25

35:25 The sons of Bilhah, Rachel’s servant, were Dan and Naphtali.

Exodus 1:2

1:2 Reuben, Simeon, Levi, and Judah,