Thematic Bible: Concubines might be dismissed

Nevertheless, when Sarah saw the son of Hagar the Egyptian whom Hagar had borne to Abraham making fun of Isaac, she told Abraham, "Throw out this slave girl, along with her son, because this slave's son will never be a co-heir with my son Isaac!" Abraham was very troubled about what was being said about his son, read more.
but God told Abraham, "Don't be troubled about the youth and your slave girl. Pay attention to Sarah in everything she tells you, because your offspring are to be named through Isaac. Nevertheless, I will make the slave girl's son into a nation, since he, too, is your offspring." So early the next morning, Abraham got up, took bread and a leather bottle of water, gave them to Hagar, and placed them on her shoulder. He then sent her away, along with the child. She went off and roamed in the Beer-sheba wilderness.