Genesis 6:12-14, 19-20, 22

So God looked upon the earth, and indeed it was corrupt; for all flesh had corrupted their way on the earth. And God said to Noah, “The end of all flesh has come before Me, for the earth is filled with violence through them; and behold, I will destroy them with the earth. Make yourself an ark of gopherwood; make rooms in the ark, and cover it inside and outside with pitch.

And of every living thing of all flesh you shall bring two of every sort into the ark, to keep them alive with you; they shall be male and female. Of the birds after their kind, of animals after their kind, and of every creeping thing of the earth after its kind, two of every kind will come to you to keep them alive.

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