Exodus 25:17

And thou shalt make a propitiatory, a lid of pure gold; the length of two cubits and a half, and the breadth of a cubit and a half.

And 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.

You shall make a mercy seat of pure gold. Two and a half cubits shall be its length, and a cubit and a half its width.