Leviticus 2:13 links salt explicitly with covenant in the offering law: every grain offering is to include “the salt of the covenant of thy God.” Second Chronicles 13:5 later describes YHWH’s grant of kingship to David’s house as “a covenant of salt,” showing that salt-covenant imagery develops beyond sacrificial procedure into language of enduring covenant obligation.

Leviticus 2:13 and Numbers 18:19 both use covenant-of-salt language. The phrase strongly links salt with durable covenant obligation, though Leviticus itself does not explain the symbol.

Mark 9:49–50 combines sayings about being salted and having salt in yourselves. Leviticus 2:13 requires salt with offerings and calls it “the salt of the covenant,” creating a possible sacrificial-covenant resonance. The relationship remains uncertain because Mark does not identify Leviticus and the salt sayings are textually and interpretively difficult.

Salt accompanies offerings and appears in 'covenant of salt' expressions. These texts can enrich the saying, but Luke's immediate point is usefulness versus uselessness in discipleship; a direct covenant-of-salt allusion cannot be assumed.