John Calvin on Genesis 8:17-19

17. That they may breed abundantly , etc . With these words the Lord would cheer the mind of Noah, and inspire him with confidence, that a seed had been preserved in the ark which should increase till it replenished the whole earth. In short, the renovation of the earth is promised to Noah; to the end that he may know that the world itself was inclosed in the ark, and that the solitude and devastation, at the sight of which his heart might faint, would not be perpetual.