וְעָשִׂ֤יתָ בַדִּים֙ לַמִּזְבֵּ֔חַ בַּדֵּ֖י עֲצֵ֣י שִׁטִּ֑ים וְצִפִּיתָ֥ אֹתָ֖ם נְחֹֽשֶׁת׃
And thou shalt make staves for the altar, staves of acacia-wood, and overlay them with brass.
Read midrashic interpretation of Exodus 27:6: and classical rabbinic exegesis.