And you, be ye fruitful and multiply. He again turns his discourse to Noah and his sons, exhorting them to the propagation of offspring: as if he would say, You see that I am intent upon cherishing and preserving mankind, do you therefore also attend to it.' At the same time, in commending to them the preservation of seed, he deters them from murder, and from unjust acts of violence. Yet his chief end was that to which I have before alluded, that he might encourage their dejected minds. For in these words is contained not a bare precept, but also a promise.

And you, be ye fruitful and multiply,.... Instead of taking away the lives of men, the great concern should be to multiply them; and this indeed is one reason of the above law, to prevent the decrease and ruin of mankind; and which was peculiarly needful, when there were so few men in the world as only four, and therefore it is repeated in stronger terms:
bring forth abundantly in the earth, and multiply therein; that the whole earth might be overspread with men, and repeopled sufficiently, as it was by the sons of Noah, see Genesis 9:19.