1. Mose 21:8

Expulsion of Ishmael. - The weaning of the child, which was celebrated with a feast, furnished the outward occasion for this. Sarah saw Ishmael mocking, making ridicule on the occasion. "Isaac, the object of holy laughter, was made the butt of unholy wit or profane sport. He did not laugh (צחק), but he made fun (מצחק). The little helpless Isaac a father of nations! Unbelief, envy, pride of carnal superiority, were the causes of his conduct. Because he did not understand the sentiment, 'Is anything too wonderful for the Lord?' it seemed to him absurd to link so great a thing to one so small" (Hengstenberg). Paul calls this the persecution of him that was after the Spirit by him that was begotten after the flesh (Gal 4:29), and discerns in this a prediction of the persecution, which the Church of those who are born after the spirit of faith endures from those who are in bondage to the righteousness of the law. Gen 21:9-13 Sarah therefore asked that the maid and her son might be sent away, saying, the latter "shall not be heir with Isaac." The demand, which apparently proceeded from maternal jealousy, displeased Abraham greatly "because of his son," - partly because in Ishmael he loved his own flesh and blood, and partly on account of the promise received for him (Gen 17:18 and Gen 17:20). But God (Elohim, since there is no appearance mentioned, but the divine will was made known to him inwardly) commanded him to comply with Sarah's demand: "for in Isaac shall seed (posterity) be called to thee." This expression cannot mean "thy descendants will call themselves after Isaac," for in that case, at all events, זרעך would be used; for "in (through) Isaac shall seed be called into existence to thee," for קרא does not mean to call into existence; but, "in the person of Isaac sha…

In this chapter we have, I. Isaac, the child of promise born into Abraham's family (Gen 21:1-8). II. Ishmael, the son of the bondwoman, cast out of it (Gen 21:9-21). III. Abraham's league with his neighbour Abimelech (Gen 21:22-32). IV. His devotion to his God (Gen 21:33).

21:8-21 God used the incident of Ishmael’s mocking Isaac to separate Ishmael and Hagar from the family and the child of promise. They would constantly threaten the promised descendant if they remained with the family. 21:8-9 The feast for Isaac’s weaning probably occurred when he was three and Ishmael was about seventeen years old (16:16). Sarah saw Ishmael making fun of her son, Isaac: The verb metsakheq (“making fun of”) is related to the word for “laughter”; this theme (21:6) is given a sour twist by Ishmael’s mockery.