Genesis 21:12

Hearken unto her voice. From a human point of view it seems strange that God should approve of Sarah’s somewhat selfish request. Although God was ready to bless Ishmael (see chs. 16:10; 21:13), and did not directly censure Abraham on account of Hagar, yet He never recognized Abraham’s marriage to her. To God, she was ever the “bondwoman,” not his wife. Ishmael’s incessant “mocking” (see on v. 9) made it apparent that he would continue to disturb the peace and harmony of the household during Abraham’s lifetime, and that upon Abraham’s death he would probably press his claim to the birthright by force. It was now clear that Ishmael could no longer remain in the home without danger to God’s plan for Isaac. Abraham had not sought God’s advice in taking Hagar, and that hasty act now made necessary the expulsion of a son whom he dearly loved. At the same time, God comforted Abraham with the assurance that Ishmael, as his offspring, would also share in some of the promise made to him and would become a great nation.