The Popular Commentary by Paul E. Kretzmann - Ezekiel 43:13-27
Description and Dedication of the Altar of Burnt Offering v. 13. And these are the measures of the altar after the cubits (the cubit is a cubit and an hand-breadth, the so-called sacred cubit) even the bottom, literally, "the bosom," probably a paneled recess in the side of the altar, shall be a cubit and the breadth a cubit, and the border thereof by the edge thereof round about shall be a span, that is, the molding, or ornamental border, enclosing such a panel; and this shall be the... read more
George Haydock's Catholic Bible Commentary - Ezekiel 43:14
Cubit. they were each a cubit broad, but this greater means higher up. Some assert that the priests stood on this base to avoid treading on the altar, when they place the wood or victims. But it would be too low; and steps were made for that purpose. The altar was ten, or rather twelve cubits high, and as many broad. Solomon's was ten high and twenty broad. Herod's was a square of forty cubits, raised fifteen from the ground. (Calmet) read more