Elisha healed the bad water in Jericho with salt.
2 Kings 2:19 - 22
ESV - 19 Now the men of the city said to Elisha, "Behold, the situation of this city is pleasant, as my lord sees, but the water is bad, and the land is unfruitful. 20 He said, "Bring me a new bowl, and put salt in it." So they brought it to him.
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