The fowl, the cattle, and the creeping thing are the 3 tiers of force within a person: birds are the airy thoughts flying through the head, cattle the settled bodily powers of the middle, creeping things the low instincts moving along the ground of the flesh. The number 2 is the pairing of every force with its opposite, each inner power held as a balanced pair so it can be carried through the flood.
Within a person every energy from the highest thought to the lowest instinct is gathered in its pair and sealed into the ark of the enduring self. Nothing true in the body is lost; each power is kept whole, opposite by opposite.
Fowls: the airy thoughts and mental energies that fly through the region of the head
Cattle: the settled bodily powers and vital forces of the middle nature
Creeping thing: the low instincts and appetites that move along the ground of the flesh