Exodus 25:15-18

15The staves shall be in the rings of the ark: they shall not be taken from it. 16And thou shalt put into the ark the testimony which I shall give thee. 17And thou shalt make a mercy-seat of pure gold: two cubits and a half shall be the length thereof, and a cubit and a half the breadth thereof. 18And thou shalt make two cherubim of gold; of beaten work shalt thou make them, at the two ends of the mercy-seat.