Genesis 30:3

Then she said , Here is my servant Bilhah ; go in to her, so that she may give birth on my behalf , that even I may have children through her.

Then she said, “Here is Bilhah, my servant. Sleep with her so that she can bear children for me and I too can build a family through 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.