Mizbēaḥ derives from the verb zābaḥ (H2076), 'to slaughter, sacrifice.' An altar was literally a 'place of slaughter' — the focal point where animal sacrifice was performed. The word appears 402 times, making it one of the most frequently used cult terms in the Hebrew Bible. Altars were built from uncut field stones (Exodus 20:25), earthen mounds, or bronze (the Tabernacle's bronze altar in the courtyard) and gold (the golden altar of incense inside the Tabernacle). Every major patriarch built altars at places of divine encounter: Noah after the flood (Genesis 8:20), Abraham at Shechem (Genesis 12:7) and Moriah (Genesis 22), Isaac, Jacob, and Moses.
The mizbēaḥ represents the central meeting point between God and worshiper — mediated by sacrifice. Blood on the altar enacted atonement; fire consuming the sacrifice represented divine acceptance. The book of Hebrews interprets the entire OT altar system as a shadow pointing forward to Christ's once-for-all sacrifice. Hebrews 13:10 says 'We have an altar from which those who minister at the tabernacle have no right to eat' — referring to the cross. In Revelation, the altar appears in heaven (Revelation 6:9; 8:3-5), where the prayers of saints mingle with incense, and from which divine judgments proceed — showing that the altar concept is not abolished but fulfilled and transcended.