The sheet did not contain all the animals that exist, but all kinds of animals. It was a representation of all the living animals that God has created (Genesis 1:20, Genesis 1:24, Genesis 1:30; Genesis 6:20).1 This means that it included unclean animals which were prohibited for consumption under the terms of the old covenant (Leviticus 11:1–47; Deuteronomy 14:1–29).2
12 In it were all kinds of animals and reptiles and birds of the air.