Genesis 30:3

And Rachel said to Jacob, Behold my handmaid Balla, go in to her, and she shall bear upon my knees, and I also shall have children by her.

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.

She said, “Behold, my maid Bilhah. Go in to her, that she may bear on my knees, and I also may obtain children by her.”