Genesis 6:17-18, 22

And behold, I Myself am bringing floodwaters on the earth, to destroy from under heaven all flesh in which is the breath of life; everything that is on the earth shall die. But I will establish My covenant with you; and you shall go into the ark—you, your sons, your wife, and your sons’ wives with you.

Thus Noah did; according to all that God commanded him, so he did.