The altar of sacrifice which 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, with a view to introduce definite propositions and symbolic numbers. See Plan L.
The bottom - The base (I) of the altar 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 which was not covered by the “lower settle.”
The higher place - the base, literally back; the base is called the back because the altar rested upon it.