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

And God saw the earth, and behold, it was corrupt, for all flesh had corrupted their way on the earth. And God said to Noah, “I have determined to make an end of all flesh, for the earth is filled with violence through them. Behold, I will destroy them with the earth. Make yourself an ark of gopher wood. Make rooms in the ark, and cover it inside and out 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 according to their kinds, and of the animals according to their kinds, of every creeping thing of the ground, according to its kind, two of every sort shall come in to you to keep them alive.

Noah did this; he did all that God commanded him.