Albert Barnes Commentary 2 Kings 2:20

"And he said, Bring me a new cruse, and put salt therein. And they brought it to him." — 2 Kings 2:20 (ASV)

The “new jar” and the “salt” are evidently chosen with regard to symbolism. The foul stream represents sin, and to cleanse it, emblems of purity must be taken. Hence the choice of the clean “new” dish, previously unused and thus untainted, and the salt, a common scriptural symbol of incorruption (Ezekiel 43:24; Matthew 5:13).