Exodus 27:6

4You shall make a grating for it of network of bronze. On the net you shall make four bronze rings in its four corners.

5You shall put it under the ledge around the altar beneath, that the net may reach halfway up the altar.

6You shall make poles for the altar, poles of acacia wood, and overlay them with bronze.

7Its poles shall be put into the rings, and the poles shall be on the two sides of the altar when carrying it.

8You shall make it hollow with planks. They shall make it as it has been shown you on the mountain.