Salt has accompanied every offering made to God, as required in Leviticus 2:13, where the grain offering must be seasoned with salt so that the salt of the covenant of your God is never lacking from it. Because the altar represents God's table and salt always appears on human tables, this substance must likewise appear at His, signifying that the offering forms part of a shared meal. Throughout history, agreements between people were confirmed by eating and drinking together with salt, and because salt both seasons and preserves food from decay, it came to symbolize incorruptibility, permanence, purity, fidelity, and durability. A covenant confirmed with salt therefore signified an everlasting covenant that could not be broken. This truth appears explicitly in Numbers 18:19, where God declares the heave offerings given to Aaron and his descendants to be a covenant of salt forever before the Lord. The same permanence applies to believers who present themselves as living sacrifices, holy and acceptable to God. Such a sacrifice must be salted, which requires lives marked by purity without spot or blemish and by persevering fidelity in obedience to the unchanging God. Salt thus stands opposite leaven, preserving from corruption and ensuring that the living sacrifice remains perpetual rather than momentary.

Salt represents inviolability, purity, and permanence in the covenant of salt. Scripture applies this term to the nation in Leviticus 2:13, to the priests in Numbers 18:19, and to David's royal line in II Chronicles 13:5. Each covenant is described as holy and everlasting because it originates with God. In the grain offering, salt must accompany every sacrifice so that the offering itself becomes a visible sign of an unalterable relationship. Jesus' call for disciples to be the salt of the earth draws on this imagery. Paul develops the same thought in Romans 12:1-2 by urging believers to present their bodies as living sacrifices that are holy and acceptable to God. Such sacrifices reflect the purity and permanence once symbolized by salt in the Temple offerings. Because Christians possess the Holy Spirit and live under the New Covenant, they alone can perform these spiritual sacrifices. Their conduct therefore embodies the same qualities of purity and permanence that salt signified in the ancient covenants, demonstrating sacrificial goodness toward others and thereby fulfilling the duties of discipleship within the Sermon on the Mount.