Exodus 38:3-7

And he made all the vessels of the altar, the pots, and the shovels, and the basons, and the fleshhooks, and the firepans: all the vessels thereof made he of brass.

And he made for the altar a brasen grate of network under the compass thereof beneath unto the midst of it.

And he cast four rings for the four ends of the grate of brass, to be places for the staves.

And he made the staves of shittim wood, and overlaid them with brass.

And he put the staves into the rings on the sides of the altar, to bear it withal; he made the altar hollow with boards.