Genesis 6:19 "And of every living thing of all flesh, you shall bring two of every kind into the ark, to keep them alive with you; they shall be male and female.

Genesis 6:20 "Of the birds after their kind, and of the animals after their kind, of every creeping thing of the ground after its kind, two of every kind will come to you to keep them alive.

Genesis 7:2 "You shall take with you of every clean animal by sevens, a male and his female; and of the animals that are not clean two, a male and his female;

Genesis 7:3 also of the birds of the sky, by sevens, male and female, to keep offspring alive on the face of all the earth. (NASB ©1995)