9 But Sarah saw Ishmael-the son of Abraham and her Egyptian servant Hagar-making fun of her son, Isaac. 10 So she turned to Abraham and demanded, "Get rid of that slave woman and her son. He is not going to share the inheritance with my son, Isaac. I won't have it!" 11 This upset Abraham very much because Ishmael was his son. 12 But God told Abraham, "Do not be upset over the boy and your servant. Do whatever Sarah tells you, for Isaac is the son through whom your descendants will be counted. 13 But I will also make a nation of the descendants of Hagar's son because he is your son, too."
14 So Abraham got up early the next morning, prepared food and a container of water, and strapped them on Hagar's shoulders. Then he sent her away with their son, and she wandered aimlessly in the wilderness of Beersheba. 15 When the water was gone, she put the boy in the shade of a bush. 16 Then she went and sat down by herself about a hundred yards away. "I don't want to watch the boy die," she said, as she burst into tears. 17 But God heard the boy crying, and the angel of God called to Hagar from heaven, "Hagar, what's wrong? Do not be afraid! God has heard the boy crying as he lies there. 18 Go to him and comfort him, for I will make a great nation from his descendants." 19 Then God opened Hagar's eyes, and she saw a well full of water. She quickly filled her water container and gave the boy a drink. 20 And God was with the boy as he grew up in the wilderness. He became a skillful archer, 21 and he settled in the wilderness of Paran. His mother arranged for him to marry a woman from the land of Egypt.
Matthew Henry's Commentary on Genesis 21:9-21
Commentary on Genesis 21:9-13
(Read Genesis 21:9-13)
Let us not overlook the manner in which this family matter instructs us not to rest in outward privileges, or in our own doings. And let us seek the blessings of the new covenant by faith in its Divine Surety. Ishmael's conduct was persecution, being done in profane contempt of the covenant and promise, and with malice against Isaac. God takes notice of what children say and do in their play; and will reckon with them, if they say or do amiss, though their parents do not. Mocking is a great sin, and very provoking to God. And the children of promise must expect to be mocked. Abraham was grieved that Ishmael should misbehave, and Sarah demand so severe a punishment. But God showed him that Isaac must be the father of the promised Seed; therefore, send Ishmael away, lest he corrupt the manners, or try to take the rights of Isaac. The covenant seed of Abraham must be a people by themselves, not mingled with those who were out of covenant: Sarah little thought of this; but God turned aright what she said.
Commentary on Genesis 21:14-21
(Read Genesis 21:14-21)
If Hagar and Ishmael had behaved well in Abraham's family, they might have continued there; but they were justly punished. By abusing privileges, we forfeit them. Those who know not when they are well off, will be made to know the worth of mercies by the want of them. They were brought to distress in the wilderness. It is not said that the provisions were spent, or that Abraham sent them away without money. But the water was spent; and having lost their way, in that hot climate Ishmael was soon overcome with fatigue and thirst. God's readiness to help us when we are in trouble, must not slacken, but quicken our endeavours to help ourselves. The promise concerning her son is repeated, as a reason why Hagar should bestir herself to help him. It should engage our care and pains about children and young people, to consider that we know not what great use God has designed them for, and may make of them. The angel directs her to a present supply. Many who have reason to be comforted, go mourning from day to day, because they do not see the reason they have for comfort. There is a well of water near them in the covenant of grace, but they are not aware of it, till the same God that opened their eyes to see their wound, opens them to see their remedy. Paran was a wild place, fit for a wild man; such as Ishmael. Those who are born after the flesh, take up with the wilderness of this world, while the children of the promise aim at the heavenly Canaan, and cannot be at rest till they are there. Yet God was with the lad; his outward welfare was owing to this.