2 Kings 2:21

And he went forth unto the spring of the waters, where the brook welled up from the ground, and cast the salt in there, as a prophetical, symbolical action to indicate what the Lord was about to do, and said, Thus saith the Lord, I have healed these waters; there shall not be from thence any more death or barren land, that is, barrenness, of which they had complained. This miracle was intended to convey to the minds of the people the fact of the blessings of God in the prophetic activities of Elisha.