Adam Clarke on Exodus 30:18

A laver of brass - כיור kiyor sometimes signifies a caldron, 1Sam 2:14; but it seems to signify any large round vessel or basin used for washing the hands and feet. There were doubtless cocks or spigots in it to draw off the water, as it is not likely the feet were put into it in order to be washed. The foot of the laver must mean the pedestal on which it stood.