Archaeology shows that the horns of the altar were raised parts at the four corners of the altar. They projected upward from each corner.
These horns may have helped keep the wood and offerings from falling off the altar (see Psalm 118:27). They also had meaning related to beliefs about God. The horns represented God’s gracious care for his people.
If a person held onto the horns of the altar, that person was asking for mercy in judgment (see 1 Kings 1:50–51; 2:28). This action showed a request for protection or leniency.
The priests put blood on the horns during atonement and purification ceremonies (special rituals to deal with sin and uncleanness; see Exodus 29:12; Leviticus 4:7).