Genesis 30:3-9

3She 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.”

4So Rachel gave him her servant Bilhah as a wife, and Jacob had marital relations with her.

5Bilhah became pregnant and gave Jacob a son.

6Then Rachel said, “God has vindicated me. He has responded to my prayer and given me a son.” That is why she named him Dan.

7Bilhah, Rachel’s servant, became pregnant again and gave Jacob another son.

8Then Rachel said, “I have fought a desperate struggle with my sister, but I have won.” So she named him Naphtali.

9When Leah saw that she had stopped having children, she gave her servant Zilpah to Jacob as a wife.