2 Kings 2:20-22 NIV

20 "Bring me a new bowl," he said, "and put salt in it." So they brought it to him.
21 Then he went out to the spring and threw1 the salt into it, saying, "This is what the LORD says: 'I have healed this water. Never again will it cause death or make the land unproductive.' "

References for 2 Kings 2:21

22 And the water has remained wholesome2 to this day, according to the word Elisha had spoken.

References for 2 Kings 2:22