“Of every clean beast thou shalt take to thee by sevens, the male and his female: and of beasts that are not clean by two, the male and his female.” God says that to Noah in Genesis 7:2, shortly after the instruction everyone remembers. Did Noah take two of every animal, then? Of some. Two of the animals that were not clean, and sevens of the clean ones and of the birds.
The first instruction
The pairs are real, and the picture on the nursery wall is right about them.
And of every living thing of all flesh, two of every sort shalt thou bring into the ark, to keep them alive with thee; they shall be male and female. Of fowls after their kind, and of cattle after their kind, of every creeping thing of the earth after his kind, two of every sort shall come unto thee, to keep them alive.
Genesis 6:19-20 (KJV)
Two of every sort, male and female, to keep each kind alive. The chapter closes on Noah doing it: “Thus did Noah; according to all that God commanded him, so did he.”
The number depends on the animal
At the start of chapter seven, God gives the instruction again, and this time the number depends on the animal.
Of every clean beast thou shalt take to thee by sevens, the male and his female: and of beasts that are not clean by two, the male and his female. Of fowls also of the air by sevens, the male and the female; to keep seed alive upon the face of all the earth.
Genesis 7:2-3 (KJV)
The second instruction makes the first one exact. The unclean animals still come by two. The clean ones come by sevens, and so do the birds, all of them, with the reason given right there: to keep seed alive.
How many is “by sevens”? The King James wording can be read as seven animals or as seven pairs. The World English Bible reads pairs: “seven pairs” at 7:2. Both readings give more than two.
What made an animal clean? Genesis does not stop to say, as if Noah already knew. The law that spells out clean and unclean for Israel comes much later, through Moses, in Leviticus 11. A clean beast is one that “parteth the hoof, and is clovenfooted, and cheweth the cud.” Deuteronomy names the familiar ones, “the ox, the sheep, and the goat.” The camel and the swine are among its examples of unclean. Leviticus 11 closes by naming its own purpose: “To make a difference between the unclean and the clean, and between the beast that may be eaten and the beast that may not be eaten.”
Memory keeps the first, simpler count here. In Eden it added something instead: Genesis never names the fruit, and tradition supplied the apple.
Two and two
The verse people quote back is the loading scene, and it does say pairs.
Of clean beasts, and of beasts that are not clean, and of fowls, and of every thing that creepeth upon the earth, There went in two and two unto Noah into the ark, the male and the female, as God had commanded Noah.
Genesis 7:8-9 (KJV)
Taken as a head count, that would clash with verse two. Taken as a picture of how they went in, in pairs, male with female, clean and unclean alike, it fits. Verses 15 and 16 say it again and then close the door: “And they went in unto Noah into the ark, two and two of all flesh, wherein is the breath of life. And they that went in, went in male and female of all flesh, as God had commanded him: and the LORD shut him in.”
Some readers explain the two counts by older sources woven into the flood story. The story as we have it gives both counts and means both, and the way it ends puts clean animals on the altar.
The first altar
When the water is gone, the animals go out, and the first thing the text records Noah doing on the dry ground is this.
And Noah builded an altar unto the LORD; and took of every clean beast, and of every clean fowl, and offered burnt offerings on the altar.
Genesis 8:20 (KJV)
Clean beasts and clean birds, the ones Noah was told to take by sevens. Genesis never says that was the reason for the sevens. It only shows the altar. A single pair could not have survived it. Seven could.
Then the LORD speaks.
And the LORD smelled a sweet savour; and the LORD said in his heart, I will not again curse the ground any more for man’s sake; for the imagination of man’s heart is evil from his youth; neither will I again smite any more every thing living, as I have done. While the earth remaineth, seedtime and harvest, and cold and heat, and summer and winter, and day and night shall not cease.
Genesis 8:21-22 (KJV)
The LORD smells the offering and says in his heart that he will not curse the ground again, and he says it knowing the human heart has not changed. The promise does not wait for people to get better. It rests on him.
Past the head count, the story leaves an altar on ground just dried out, smoke going up from it, and a promise made over it that is kept every time a field is sown, every winter that ends, every morning, and every harvest gathered in.