Albert Barnes Commentary Ezekiel 43:13

"And these are the measures of the altar by cubits (the cubit is a cubit and a handbreadth): the bottom shall be a cubit, and the breadth a cubit, and the border thereof by the edge thereof round about a span; and this shall be the base of the altar." — Ezekiel 43:13 (ASV)

The altar of sacrifice that stood in the inner court, not the altar of incense described (Ezekiel 41:22). In the temple of the vision, the dimensions differ from those of the tabernacle (Exodus 27:1) and of Solomon’s Temple (2 Chronicles 4:1), in order to introduce definite propositions and symbolic numbers. See Plan L.

The bottom – The base (I) of the altar is so called because it forms with its “border” (K) a kind of socket to receive the “lower settle” (L). It was to be “a cubit” in depth.

The “breadth” is the breadth of that portion of the base that was not covered by the “lower settle.”

The higher place – This refers to the base (literally, back); the base is called the back because the altar rested upon it.