TSK · Genesis 29:24

Now Sarai, Abram's wife, bare him no children: and she had a handmaid, an Egyptian, whose name was Hagar.

When Leah saw that she had left off bearing, she took Zilpah her handmaid, and gave her to Jacob to wife.

These are the sons of Zilpah, whom Laban gave to Leah his daughter; and these she bare unto Jacob, even sixteen souls.