There was no excuse for worthless salt in Israel. The region was blessed with large deposits of high quality rocksalt and, thanks to the Dead Sea, had a vast capability for producing refined salt. Unlike the majority of refined salt production which was coastal, this was not suceptible to interruption by flooding.
(Matt 5:13 WEB)5:13 “You are the salt of the earth, but if the salt has lost its flavour, with what will it be salted? It is then good for nothing, but to be cast out and trodden under the feet of men.”
Within Israel, God’s representatives (such as the Levites and the House of David) served in accord with covenants “of salt.” They were supposed to preserve Israel’s good standing with God, just as salt preserves against decay. If a nation, organisation, or group has ever espoused Christ, then its leaders carry a similar responsibility before God.
Jesus plays with the dual meaning that “lost its flavour” has in secular Greek society, for the phrase also translates as “become foolish.” If those entrusted with the task of preserving their nation, become foolish through forsaking God’s wisdom, then they are good for nothing.
The covenants between God and his people specified what would happen if such a group’s service became worthless. Their society would slowly rot and its prosperity perish. They would also suffer increased foreign domination until these worthless people, and those who followed them, are thrown out of their heritage and become downtrodden exiles amongst the nations. A situation that would prevail at least until they came to their senses and came under “salty” leaders.
. . . commentary continues withMatt 5:14-16
This page is just an overview. For a detailed analysis of Matt 5:13, with supporting material and citations, see the further notes on Matt 5:13.