Genesis 16:1-2

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

And Sarai said unto Abram, Behold now, Jehovah hath restrained me from bearing; go in, I pray thee, unto my handmaid; it may be that I shall obtain children by her. And Abram hearkened to the voice of Sarai.