Exodus 38:5-7

American Standard Version

⁵ And he cast four rings for the four ends of the grating of brass, to be places for the staves. ⁶ And he made the staves of acacia wood, and overlaid them with brass. ⁷ And he put the staves into the rings on the sides of the altar, wherewith to bear it; he made it hollow with planks.