2 Kings 2:19-22

19One day, the leaders in Jericho said to Elisha, ‘Please listen to us, sir. You can see that our city is in a good place. But the water here is bad. The land does not give us good crops.’

20Elisha said, ‘Bring a new bowl to me with some salt in it.’ So they brought it to him.

21Then Elisha went out to the city's spring of water. He threw the salt into it. He said, ‘This is what the Lord says: “I have made this water clean again. It will no longer cause people to die. The land will no longer be useless for crops.” ’

22Since that time, the water has always been pure. This is what Elisha had said would happen.