Leviticus 2:11-13

So salt was an indispensable part of the offerings. As it says, every offering had to have an offering of salt with it. Here it is also linked with their covenant with God, the Old Covenant. It is called a covenant of salt. Matter of fact, this term is used at least three times in Scripture. Here in Leviticus 2:13 with the whole nation; in Numbers 18:19, a covenant of salt is made with the priests, Aaron's sons; and in II Chronicles 13:5, a covenant of salt is made with David the king, that he would have one of his sons on the throne forever.

Now, as blatant as the description here is, as much as salt is front and center in this, it is hard to pin down what salt symbolizes in the offerings. But one of the good guesses that I found of what salt represents here is inviolability. That it cannot be violated, if you will. In this way, it represents that the covenant is—famous word in the Declaration of Independence—inalienable, which means it cannot be taken away, and unalterable, which means it is not changeable. And so, in that way, if you think of a sacrifice with salt showing its inviolability, it means that it cannot be taken away, it cannot be changed, and because it is made with God, it is sacred and holy.

Putting all those words aside and kind of getting it down to its brass tacks, in this way salt indicates purity and permanence. And this is the same indication of all the covenants of salt. They were all said to be forever. They were all made with God, and thus holy. So what we could say is a covenant of salt, let us say, is a holy, everlasting covenant. And if you want to get another reference for salt signifying purity, Jericho's water was purified with salt when Elisha threw salt in the spring there at Jericho. That is at II Kings 2:21.