Hebrew mizbe'ach ha'olah, "altar of the burnt offering." The largest piece of tabernacle furniture — a square altar 5 cubits by 5 cubits by 3 cubits high (roughly 7'6" x 7'6" x 4'6"), framed in acacia wood and overlaid with bronze (Exodus 27:1-8, 38:1-7). In Solomon's temple the altar was much larger (2 Chronicles 4:1 — 20 cubits square, 10 cubits high). Stationed in the courtyard, it was the first thing anyone approaching the tabernacle saw. Horns projected from its four corners; a bronze grating held the fire; rings and poles allowed portability. Here the daily burnt offerings, the sin offerings, the peace offerings, and the trespass offerings were consumed by perpetual fire — a fire that the priests were commanded never to let go out (Leviticus 6:13).
The brazen altar taught Israel — and teaches Christians — that no approach to God is possible except through atoning sacrifice. Three dimensions. (1) First thing encountered. When an Israelite brought an offering, he passed through the courtyard gate and immediately faced the altar. You cannot get to the Holy Place (symbolizing deeper fellowship) without first dealing with the altar. Typologically: you cannot know God without first dealing with sin at the cross. (2) Perpetual fire. The command that the fire should never go out speaks of continuous availability of atonement. Any Israelite who sinned could at any time bring a sacrifice, and fire was waiting. So with the cross — the way of access is always open (Hebrews 10:19-20). (3) Horns. The four horns of the altar became places of refuge for those who feared unjust execution — Adonijah (1 Kings 1:50) and Joab (1 Kings 2:28) both fled to "take hold of the horns of the altar." The altar was sanctuary; the atoning sacrifice was shelter. Christ fulfills the pattern as the true altar (Hebrews 13:10), the once-for-all sacrifice (Hebrews 10:10), and the refuge of all who flee to Him. "Whoever comes to me I will never cast out" (John 6:37) is the horn-grabbing promise of the new covenant.