Foursquare shall it be. — Of the same shape with “the brazen altar” (Exodus 27:1), but much smaller — two cubits high instead of three cubits, and a cubit square at top instead of five cubits. This small space was ample for the burning of so precious a material, which could only be offered in small quantities.
The horns thereof. — Comp. Exodus 27:2, and Note 1, ad loc.
Shall be of the same — i.e., of one piece with the altar, not made separately, and then attached to it.