Exodus 38:3-7

He also made all the utensils of the altar, the pails, the shovels, the basins, the meat-forks, and the firepans; he made all its utensils of bronze.

And he made for the altar a grating of bronze netting beneath, under its ledge, reaching halfway up.

He also cast four rings on the four ends of the bronze grating as holders for the poles.

He made the poles of acacia wood and overlaid them with bronze.

Then he inserted the poles into the rings on the sides of the altar, with which to carry it. He made it hollow with planks.