Genesis 7:2-4

7:2 You must take with you seven of every kind of clean animal, the male and its mate, two of every kind of unclean animal, the male and its mate, 7:3 and also seven of every kind of bird in the sky, male and female, to preserve their offspring on the face of the earth. 7:4 For in seven days I will cause it to rain on the earth for forty days and forty nights, and I will wipe from the face of the ground every living thing that I have made.”