Exodus 38:3-7

3He 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. 4And he made for the altar a grating of bronze netting beneath, under its ledge, reaching halfway up. 5He also cast four rings on the four ends of the bronze grating as holders for the poles. 6He made the poles of acacia wood and overlaid them with bronze. 7Then he inserted the poles into the rings on the sides of the altar, with which to carry it. He made it hollow with planks.