Genesis 21

CHAPTER 21Ge 21:1-13. Birth of Isaac.1. the Lord visited Sarah—The language of the historian seems designedly chosen to magnify the power of God as well as His faithfulness to His promise. It was God's grace that brought about that event, as well as the raising of spiritual children to Abraham, of which the birth of this son was typical [Calvin].

21:1-8 Few under the Old Testament were brought into the world with such expectations as Isaac. He was in this a type of Christ, that Seed which the holy God so long promised, and holy men so long expected. He was born according to the promise, at the set time of which God had spoken. God's promised mercies will certainly come at the time which He sets, and that is the best time. Isaac means laughter, and there was good reason for the name, ch. 17:17; 18:13. When the Sun of comfort is risen upon the soul, it is good to remember how welcome the dawning of the day was. When Sarah received the promise, she laughed with distrust and doubt. When God gives us the mercies we began to despair of, we ought to remember with sorrow and shame our sinful distrust of his power and promise, when we were in pursuit of them. This mercy filled Sarah with joy and wonder. God's favours to his covenant people are such as surpass their own and others' thoughts and expectations: who could imagine that he should do so much for those that deserve so little, nay, for those that deserve so ill? Who would have said that God should send his Son to die for us, his Spirit to make us holy, his angels to attend us? Who would have said that such great sins should be pardoned, such mean services accepted, and such worthless worms taken into covenant? A short account of Isaac's infancy is given. God's blessing upon the nursing of children, and the preservation of them through the perils of the infant age, are to be acknowledged as signal instances of the care and tenderness of the Divine providence. See Ps 22:9,10; Ho 11:1,2.

Chapter 21 In this chapter we have, I. Isaac, the child of promise born into Abraham’s family (v. 1-8). II. Ishmael, the son of the bondwoman, cast out of it (v. 9–21). III. Abraham’s league with his neighbour Abimelech (v. 22–32). IV. His devotion to his God (v. 33).Verses 1-8 Long-looked-for comes at last. The vision concerning the promised seed is for an appointed time, and now, at the end, it speaks, and does not lie; few under the Old Testament were brought into the world with such expectation as Isaac was, not for the sake of any great person eminence at which he was to arrive, but because he was to be, in this very thin, a type of Christ, that seed which the holy God had so long promised and holy men so long expected. In this account of the first days of Isaac we may observe,I. The fulfilling of God’s promise in the conception and birth of Isaac, v. 1, 2. Note, God’s providences look best and brightest when they are compared with his word, and when we observe how God, in them all, acts as he has said, as he has spoken. 1. Isaac was born according to the promise. The Lord visited Sarah in mercy, as he had said. Note, No word of God shall fall to the ground; for he is faithful that has promised, and God’s faithfulness is the stay and support of his people’s faith. He was born at the set time of which God had spoken, v. 2. Note, God is always punctual to his time; though his promised mercies come not at the time we set, they will certainly come at the time he sets, and that is the best time., 2. He was born by virtue of the promise: Sarah by faith received strength to conceive Heb. 11:11. God therefore by promise gave that strength. It was not by the power of common providence, but by the power of a special promise, that Isaac was born. A sentence of death was, as it were, passed upon the second causes: Abraham was old, and Sarah old, and both as good as dead; and then the word of God took place. Note, True believers, by virtue of God’s promises, are enabled to do that which is above the power of human nature, for by them they partake of a divine nature, 2 Pt. 1:4.II. Abraham’s obedience to God’s precept concerning Isaac.1. He named him, as God commanded him, v. 3. God directed him to a name for a memorial, Isaac, laughter; and Abraham, whose office it was, gave him that name, though he might have designed him some other name of a more pompous signification. Note, It is fit that the luxuriancy of human invention should always yield to the sovereignty and plainness of divine institution; yet there was good reason for the name, for, (1.) When Abraham received the promise of him he laughed for joy, ch. 17:17. Note, When the sun of comfort has risen upon the soul it is good to remember how welcome the dawning of the day was, and with what exultation we embraced the promise. (2.) When Sarah received the promise she laughed with distrust and diffidence. Note, When God gives us the mercies we began to despair of we ought to remember with sorrow and shame our sinful distrusts of God’s power and promise, when we were in pursuit of them. (3.) Isaac was himself, afterwards, laughed at by Ishmael (v. 9), and perhaps his name bade him expect it. Note, God’s favourites are often the world’s laughing-stocks. (4.) The promise which he was not only the son, but the heir of, was to be the joy of all the saints in all ages, and that which would fill their mouths with laughter.2. He circumcised him, v. 4. The covenant being established with him, the seal of the covenant was administered to him; and though a bloody ordinance, and he a darling, yet it must not be omitted, no, nor deferred beyond the eighth day. God had kept time in performing the promise, and therefore Abraham must keep time in obeying the precept.III. The impressions which this mercy made upon Sarah.1. It filled her with joy (v. 6): "God has made me to laugh; he has given me both cause to rejoice and a heart to rejoice." Thus the mother of our Lord, Lu. 1:46, 47. Note, (1.