Charles Ellicott Commentary 2 Chronicles 13:5

"Ought ye not to know that Jehovah, the God of Israel, gave the kingdom over Israel to David for ever, even to him and to his sons by a covenant of salt?" — 2 Chronicles 13:5 (ASV)

Ought you not to know. —Literally, is it not for you to know? This is a construction characteristic of the chronicler. Abijah contrasts the moral position of his adversaries with his own, asserting the following:

1. that their separate political existence is itself an act of rebellion against Jehovah;
2. that they have abolished the only legitimate form of worship, and established in its place an illegal cultus and priesthood;
3. whereas he and his people have maintained the orthodox ritual and ministry, and are therefore assured of the divine support.

By a covenant of salt. — As or after the manner of a covenant of salt, i.e., a firm and unalterable compact . According to ancient custom, salt was indispensable at formal meals for the ratification of friendship and alliance; and only a “salt treaty” was held to be secure. Salt therefore accompanied sacrifices, as being, in fact, so many renewals of the covenant between man and God (Leviticus 2:13; Ezekiel 43:24; Leviticus 24:7 in the Septuagint).

The antique phrase, “covenant of salt,” is otherwise important, as bearing on the authenticity of this speech.