In bidding them to take wives for their sons, and to give their daughters in marriage, he speaks according to the usual order of nature; for it would be altogether unreasonable for young men and young women to seek partners for themselves, according to their own humor and fancy. God then speaks here according to the common order of things, when he bids young men not to be otherwise joined in marriage than by the consent of parents, and that young women are not to marry but those to whom they are given.
He then adds, Be ye multiplied there and not diminished; as though he had said, that the time of exile would be so long, that except they propagated, they would soon come to nothing: and God expressed this, because it was not his will that Abraham’s seed should fail. It was indeed a kind of death, when he had driven them so far, as though he had deprived them of the inheritance which he had promised to be perpetual: he, however, administers comfort here by commanding them to propagate their kind: for they could not have been encouraged to do so, except they had their eyes directed to the hope of a return. He then afforded them some taste of his mercy when he bade them not to be diminished in Chaldea. He then adds, —