God hath made me to laugh - Sarah alludes here to the circumstance mentioned Genesis 18:12; and as she seems to use the word to laugh in this place, not in the sense of being incredulous but to express such pleasure or happiness as almost suspends the reasoning faculty for a time, it justifies the observation on the above-named verse. See a similar case in Luke 24:41, where the disciples were so overcome with the good news of our Lord's resurrection, that it is said, They believed not for joy.

And Sarah said, God hath made me to laugh,.... This she said on occasion of the name of her son Isaac, which name her husband had given him by divine direction, and to which she assented. This doubtless brought to her mind her former laughing, when she first heard that she should have a son, which was in a way of diffidence and distrust; but now God having given her a son, laid a foundation for laughter of another kind, for real, solid, joy and thankfulness:

so that all that hear will laugh with me; not laugh at her, and deride her, as Piscator interprets it; but congratulate her, and rejoice with her on this occasion, as on a like one the neighbours of Elisabeth did with her, Luke 1:58.

And Sarah said, God hath made me to laugh, so that all that hear will laugh with me.

21:6 And Sarah said, God has made me to laugh - He hath given me both cause to rejoice, and a heart to rejoice. And it adds to the comfort of any mercy to have our friends rejoice with us in it, See Luke 1:58. They that hear will laugh with me - Others will rejoice in this instance of God's power and goodness, and be encouraged to trust in him.

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.