Genesis 30:4

30:4 So Rachel gave him her servant Bilhah as a wife, and Jacob had marital relations with her.

Genesis 30:9

30:9 When Leah saw that she had stopped having children, she gave her servant Zilpah to Jacob as a wife.

Genesis 16:3

16:3 So after Abram had lived in Canaan for ten years, Sarai, Abram’s wife, gave Hagar, her Egyptian servant, to her husband to be his wife.