Genesis 30:4

And when Rachel saw that she bare Jacob no children, Rachel envied her sister; and said unto Jacob, Give me children, or else I die.

And Jacob's anger was kindled against Rachel: and he said, Am I in God's stead, who hath withheld from thee the fruit of the womb?

And she said, Behold my maid Bilhah, go in unto her; and she shall bear upon my knees, that I may also have children by her.

And Bilhah conceived, and bare Jacob a son.