And he said, Bring me a new cruse, and put salt therein. And they brought it to him.

Wesley's Notes

2:20 A new cruse - That there might be no legal pollution in it which might offend God, and hinder his miraculous operation. Put salt - A most improper remedy; for salt naturally makes waters brackish, and lands barren. Hereby therefore he would shew, that this was effected solely by the Divine power, which could work either without means, or against them.

Jamieson-Fausset-Brown Bible Commentary

20. Bring me a new cruse, and put salt therein-The noxious qualities of the water could not be corrected by the infusion of salt-for, supposing the salt was possessed of such a property, a whole spring could not be purified by a dishful for a day, much less in all future time. The pouring in of the salt was a symbolic act with which Elisha accompanied the word of the Lord, by which the spring was healed [Keil].

Matthew Henry's Concise Commentary

2:19-25 Observe the miracle of healing the waters. Prophets should make every place to which they come better for them, endeavouring to sweeten bitter spirits, and to make barren souls fruitful, by the word of God, which is like the salt cast into the water by Elisha. It was an apt emblem of the effect produced by the grace of God on the sinful heart of man. Whole families, towns, and cities, sometimes have a new appearance through the preaching of the gospel; wickedness and evil have been changed into fruitfulness in the works of righteousness, which are, through Christ, to the praise and glory of God. Here is a curse on the youths of Bethel, enough to destroy them; it was not a curse causeless, for it was Elisha's character, as God's prophet, that they abused. They bade him go up, reflecting on the taking up of Elijah into heaven. The prophet acted by Divine impulse. If the Holy Spirit had not directed Elisha's solemn curse, the providence of God would not have followed it with judgment. The Lord must be glorified as a righteous God who hates sin, and will reckon for it. Let young persons be afraid of speaking wicked words, for God notices what they say. Let them not mock at any for defects in mind or body; especially it is at their peril, if they scoff at any for well doing. Let parents that would have comfort in their children, train them up well, and do their utmost betimes to drive out the foolishness that is bound up in their hearts. And what will be the anguish of those parents, at the day of judgment, who witness the everlasting condemnation of their offspring, occasioned by their own bad example, carelessness, or wicked teaching!