Exodus 27:4-8

And thou shalt make for it a grate of network of brass; and upon the net shalt thou make four brasen rings in the four corners thereof.

And thou shalt put it under the compass of the altar beneath, that the net may be even to the midst of the altar.

And thou shalt make staves for the altar, staves of shittim wood, and overlay them with brass.

And the staves shall be put into the rings, and the staves shall be upon the two sides of the altar, to bear it.

Hollow with boards shalt thou make it: as it was shewed thee in the mount, so shall they make it.