1. And the Lord visited Sarah. In this chapters not only is the nativity of Isaac related, but because, in his very birth, God has set before us a lively picture of his Church, Moses also gives a particular account of this matter. And first, he says that God visited Sarah, as he had promised. Because all offspring, flows from the kindness of God, as it is in the psalm,
‘The fruit of the womb is the gift of God;’ (Psalms 127:3;)
therefore the Lord is said, not without reason, to visit those, to whom he gives children. For although the foetus seems to be produced naturally, each from its own kind; there is yet no fecundity in animals, except so far as the Lord puts forth his own power, to fulfill what he has said, Increase and multiply. But in the propagation of the human race, his special benediction is conspicuous; and, therefore, the birth of every child is rightly deemed the effect of divine visitation. But Moses, in this place, looks higher, forasmuch as Isaac was born out of the accustomed course of nature. (433) Therefore Moses here commends that secret and unwonted power of God, which is superior to the law of nature; and not improperly, since it is of great consequence for us to know that the gratuitous kindness of God reigned, as well in the origin, as in the progress of the Church; and that the sons of God were not otherwise born, than from his mere mercy. And this is the reason why he did not make Abraham a father, till his body was nearly withered. It is also to be noticed, that Moses declares the visitation which he mentions, to be founded upon promise; ‘Jehovah visited Sarah, as he had promised.’ In these words he annexes the effect to its cause, in order that the special grace of God, of which an example is given in the birth of Isaac, might be the more perceptible. If he had barely said, that the Lord had respect unto Sarah, when she brought forth a son; some other cause might have been sought for. None, however, can doubt, that the promise, by which Isaac had been granted to his father Abraham, was gratuitous; since the child was the fruit of that adoption, which can be ascribed to nothing but the mere grace of God. Therefore, whoever wishes rightly and prudently to reflect upon the work of God, in the birth of Isaac, must necessarily begin with the promise. There is also great emphasis in the repetition, “The Lord did unto Sarah as he had spoken.” For he thus retains his readers, as by laying his hand upon them, that they may pause in the consideration of so great a miracle. Meanwhile, Moses commends the faithfulness of God; as if he had said he never feeds men with empty promises, nor is he less true in granting what he has promised, than he is liberal, and willing, in making the promise.
(433) Calvin here adds, “ Nam communis gignendi ratio, et vis illa quam Dominus hominibus indidit, in Abraham et ejus uxore cessaverat.”