And thou shalt make an altar to burn incense upon: of shittim wood shalt thou make it.
Thou shalt make an altar ... Its material was to be like that of the ark of the testimony, but its dimensions very small.
Related Commentaries of Exodus 30:1
Exodus 30:1
1 And thou shalt make an altar to burn incense upon: of shittim wood shalt thou make it.