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

God observed all this corruption in the world, for everyone on earth was corrupt. So God said to Noah, “I have decided to destroy all living creatures, for they have filled the earth with violence. Yes, I will wipe them all out along with the earth! “Build a large boat from cypress wood and waterproof it with tar, inside and out. Then construct decks and stalls throughout its interior.

Bring a pair of every kind of animal—a male and a female—into the boat with you to keep them alive during the flood. Pairs of every kind of bird, and every kind of animal, and every kind of small animal that scurries along the ground, will come to you to be kept alive.

So Noah did everything exactly as God had commanded him.