Genesis 21:7. Sarah should have given children suck — She says children, expecting, it seems, that, having received of God new strength, she would have more than one child. Here all mothers are taught their duty, which is to give their children suck if they be able. Not to do this is a sin against the God of nature, which no rank in life, no fortune nor business, can or will excuse.

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.Isaac is born according to promise, and grows to be weaned. "The Lord had visited Sarah." It is possible that this event may have occurred before the patriarchal pair arrived in Gerar. To visit, is to draw near to a person for the purpose of either chastising or conferring a favor. The Lord had been faithful to his gracious promise to Sarah. "He did as he had spoken." The object of the visit was accomplished. In due time she bears a son, whom Abraham, in accordance with the divine command, calls Isaac, and circumcises on the eighth day. Abraham was now a hundred years old, and therefore Isaac was born thirty years after the call. Sarah expressed her grateful wonder in two somewhat poetic strains. The first, consisting of two sentences, turns on the word laugh. This is no longer the laugh of delight mingled with doubt, but that of wonder and joy at the power of the Lord overcoming the impotence of the aged mother. The second strain of three sentences turns upon the object of this admiring joy. The event that nobody ever expected to hear announced to Abraham, has nevertheless taken place; "for I have borne him a son in his old age." The time of weaning, the second step of the child to individual existence, at length arrives, and the household of Abraham make merry, as was wont, on the festive occasion. The infant was usually weaned in the second or third year 1 Samuel 1:22-24; 2 Chronicles 31:16. The child seems to have remained for the first five years under the special care of the mother Leviticus 27:6. The son then came under the management of the father.3, 4. Abraham called the name of his son … Isaac … and circumcised—God was acknowledged in the name which, by divine command, was given for a memorial (compare Ge 17:19), and also in the dedication of the child by administering the seal of the covenant (compare Ge 17:10-12). What man or woman could believe so improbable a thing? Or, who but a God could have foreseen and foretold it? She saith

children, though she had but one child, either by a usual enallage of the plural number for the singular, whereby the word sons or daughters is used when there was but one, as Genesis 36:25 46:23 Numbers 26:8; or presaging, that having received from God a new strength, she might have more children. By her expression she showeth all mothers what their duty is, viz. to give their children suck when they are able to do it; and that neither greatness of quality, nor multitude of business, nor other difficulties and inconveniences, will be a sufficient excuse to those that neglect it.

And she said, who would have said unto Abraham,.... No one a year ago could ever have thought of such a thing, much less have come and told Abraham that he should have a child or children by Sarah; the thing was incredible, and next to impossible; none but God himself, or an angel from him, could have declared this, as none but he could bring it about, the thing is so marvellous and astonishing:

that Sarah should have given children suck? that she who was ninety years of age should bear a child, and suckle it, as she did; and in doing which she set an example to her daughters to do the like, since neither age nor grandeur, nor the business of her family, were any objection to this duty of nature; and her being able to do this was a clear proof that this was truly a child of her own. The plural number may be put for the singular, as it often is, see Genesis 46:23; or Sarah might think, as she had strength given her to bear and suckle one child, she might bear and suckle more; though the phrase seems only to be expressive and descriptive of her as a nursing mother:

for I have borne him a son in his old age; See Gill on Genesis 21:2.

And she said, {b} Who would have said unto Abraham, that Sarah should have given children suck? for I have born him a son in his old age.

(b) She accuses herself of ingratitude, that she did not believe the angel.