Historically, two parties sharing a lick of salt meant they were binding themselves to one another in greatest loyalty and honesty, to the point of suffering death rather than break the covenant. The truces made, the friendships and treaties sealed this way, were never taken lightly. Even the physical properties of salt echo the seriousness of a covenant made with it because it is, among other things, a preservative that prevents decay and corruption. Salt represented purification and symbolized enduring friendship, honesty, and loyalty to the ancient Hebrews.
Bringing the Salt Covenant from Bible times into our time, Dr. Trumbull, considered by scholars to be the greatest authority on Covenant making, says Jesus was talking about covenants in Matthew 5:13 – taken literally, Jesus was saying that we are God’s expression of covenant. "You are the salt of the earth; but if the salt has become tasteless, how can it be made salty again? It is no longer good for anything, except to be thrown out and trampled under foot by men.” (NAS)
