2 Kings 2:19-22

19 Then the men of the city said to Elisha, “Please notice, the situation of this city is pleasant, as my lord sees; but the water is bad, and the ground barren.”

20 And he said, “Bring me a new bowl, and put salt in it.” So they brought it to him. 

21 Then he went out to the source of the water, and cast in the salt there, and said, “Thus says the Lord: ‘I have [a]healed this water; from it there shall be no more death or barrenness.’ ” 

22 So the water remains healed to this day, according to the word of Elisha which he spoke.