Thematic Bible: Concubines might be dismissed

And Sarah saw the son of Hagar the Egyptian, whom she had borne unto Abraham, mocking. Wherefore she said unto Abraham, Cast out this handmaid and her son. For the son of this handmaid shall not be heir with my son, even with Isaac. And the thing was very grievous in Abraham's sight on account of his son. read more.
And God said unto Abraham, Let it not be grievous in thy sight because of the lad, and because of thy handmaid. In all that Sarah saith unto thee, hearken unto her voice. For in Isaac shall thy seed be called. And also of the son of the handmaid will I make a nation, because he is thy seed. And Abraham rose up early in the morning, and took bread and a bottle of water, and gave it unto Hagar, putting it on her shoulder, and gave her the child, and sent her away. And she departed, and wandered in the wilderness of Beer-sheba.