Genesis 30:16-20

When Jacob came in from the field in the evening, Leah went out to meet him and said, “You must have relations with me, for I have indeed hired you with my son’s mandrakes.” So he slept with her that night.

God listened to Leah, and she conceived and bore Jacob a fifth son.

Then Leah said, “God has given me my reward, because I gave my slave to my husband.” So she named him Issachar.

And Leah conceived again and bore a sixth son to Jacob.

Then Leah said, “God has endowed me with a good gift; finally my husband will acknowledge me as his wife, because I have borne him six sons.” So she named him Zebulun.