John Calvin Commentary Exodus 12:37

"And the children of Israel journeyed from Rameses to Succoth, about six hundred thousand on foot that were men, besides children." — Exodus 12:37 (ASV)

And the children of Israel journeyed. It is probable that they were more widely dispersed, since that district could not have contained so great a multitude, especially when the Egyptians occupied it with them. Nevertheless, because the recollection of the promise remained among them, from which some hope of their redemption was always preserved, it is not surprising that they would have preferred to be kept within narrow bounds, despite their great inconvenience, rather than separate from the main body by seeking other habitations.

That this was the particular dwelling place of the nation is also clear from what was mentioned earlier, where Moses related that they were forced into servile labor, building those fortified cities in which they could be confined as in a prison.

In the number of men he reports, he commends the incredible miracle of God’s favor in increasing and multiplying their people. Thus, the insolence of the ungodly is refuted—those who think it sufficient reason for their scoffs that this great nation could not have naturally descended from a single family in so short a time. Therefore, they burst out into unrestrained and blasphemous laughter, as if Moses were merely relating what had happened, and not rather praising the extraordinary power of God in the sudden increase of His Church.

But we know that it was no more difficult for the Creator of the whole world to exceed the ordinary course of nature in multiplying a particular nation than it was at the beginning to quickly produce many people from one man and woman, or again, after the flood, to renew the human race by a miraculous increase.

Now, this is the distinctive characteristic of the Church: in producing and preserving it, God exerts unusual power so that it may be separated from the common condition of humankind. For although it dwells on earth, its nature is, in a way, heavenly, so that the work of God may shine out more brightly in it.

It is no wonder then if, contrary to usual custom, the Church should emerge, so to speak, from nothing, and if it grows in the same way and makes continual progress. Paul sets such an example before us in Romans 4, in the person of Abraham.

But while the ungodly despisers of God reveal their foolishness in their wicked audacity when they evaluate this work of God by their own senses and by common reason, those who attempt to defend Moses with philosophical arguments also err foolishly. For his intention was very different: namely, to show that the promises were not unfulfilled—I will multiply thy seed as the stars of heaven, and as the sand which is upon the seashore (Genesis 22:17; Genesis 12:2; Genesis 15:5)—the effect of which promises was beyond human comprehension.