Now when Rachel saw that she bore Jacob no children, Rachel envied her sister, and said to Jacob, “Give me children, or else I die!”
2 And Jacob’s anger was aroused against Rachel, and he said, “Am I in the place of God, who has withheld from you the fruit of the womb?”
3 So she said, “Here is my maid Bilhah; go in to her, and she will bear a child on my knees, that I also may have children by her.” 4 Then she gave him Bilhah her maid as wife, and Jacob went in to her. 5 And Bilhah conceived and bore Jacob a son. 6 Then Rachel said, “God has judged my case; and He has also heard my voice and given me a son.” Therefore she called his name Dan. 7 And Rachel’s maid Bilhah conceived again and bore Jacob a second son. 8 Then Rachel said, “With great wrestlings I have wrestled with my sister, and indeed I have prevailed.” So she called his name Naphtali.
9 When Leah saw that she had stopped bearing, she took Zilpah her maid and gave her to Jacob as wife. 10 And Leah’s maid Zilpah bore Jacob a son. 11 Then Leah said, “A troop comes!” So she called his name Gad.12 And Leah’s maid Zilpah bore Jacob a second son. 13 Then Leah said, “I am happy, for the daughters will call me blessed.” So she called his name Asher.
-Genesis 30:1-13