The altar serves as the focal point of service within the Tabernacle courtyard. Its deliberate placement outside the inner Tent of Meeting carries a profound message: purifying a person's material and animalistic nature is a mandatory prerequisite before one can enter the realm of true holiness [חומש קהת, שפתי כהן]. This structure was not a new concept; it was the specific altar the Israelites had anticipated since the revelation at Mount Sinai, built according to the exact spiritual blueprint God had already shown Moses on the mountain [אור החיים, רש״ר הירש, אברבנאל].
Known as the Outer Altar or the Altar of the Burnt Offering, it was designed to accompany the Israelites on their journeys through the desert [רשב״ם, רבינו בחיי, ביאור יש״ר]. The command to build it from acacia wood seems to create a practical problem, as a constant fire burned upon it, and it appears to contradict an earlier instruction to build an altar of earth. The solution lies in its design: it was constructed as a hollow, roofless wooden frame. At each encampment, this frame was filled with earth and stones. The fire burned safely on top of this earthen fill, ensuring the wooden exterior was never consumed by the flames [קאסוטו, אברבנאל, העמק דבר].
The materials and structure carry deep psychological and spiritual symbolism. The acacia wood was chosen to atone for the foolishness of the Golden Calf, while the hollow wooden boards represent a person who is empty of knowledge, urging them to take this realization to heart and repent [כלי יקר]. Furthermore, the physical processing of the sacrifices on the altar mirrors the human body. The digestion and burning of the offerings parallel the human digestive system, with the altar's various dimensions and sections hinting at different internal organs [מלבי״ם].
The altar's measurements of five cubits in length and five in width correspond to the two Tablets of the Covenant, which featured five commandments on each side [רבינו בחיי, דעת זקנים]. This number also parallels the ten physical components a person inherits from their parents, reflecting the reality that human sin ultimately stems from a flesh-and-blood material nature [כלי יקר]. The requirement for the altar to be perfectly square—with entirely equal length and width—is absolute [אבן עזרא]. While the specific five-cubit dimensions were unique to the desert generation and were expanded in later Temples, the perfectly square shape, precisely aligned with the compass directions, remains a strict and permanent requirement for all future altars [העמק דבר, הכתב והקבלה, רלב״ג, רש״ר הירש].
The height of the altar presents a fascinating discussion, as a height of three cubits seems disproportionately low for such a wide surface [ביאור שטיינזלץ]. One approach understands this measurement literally: the altar was exactly three cubits high, roughly the height of an average person. This allowed the priests to perform their duties without needing a large ramp [רש״י, כלי יקר, אברבנאל]. Symbolically, this height hints at the three main leaders who redeemed Israel in the desert: Moses, Aaron, and Miriam [רבינו בחיי, דעת זקנים]. However, the primary approach among commentators is that the altar's total height was actually ten cubits. According to this view, the three-cubit measurement refers only to the uppermost, upright section of the altar, measured from a protruding ledge that surrounded it up to the flat surface where the wood and horns were placed [רש״י, רבינו בחיי, הכתב והקבלה, תורה תמימה, רלב״ג, דעת זקנים, רש״ר הירש].
Finally, the altar was coated in copper, a metal chosen specifically to atone for human brazenness. It delivers a powerful psychological message to anyone seeking forgiveness: a person should never be too ashamed to repent. Instead, they must take that same trait of boldness and use it positively to admit their wrongdoings and draw close to God once again [כלי יקר, אלשיך].