מלכים ב ב׳:י״ט-כ״ב

והמים רעים. ומחמת המים, הארץ משכלת את יושביה לקברם, אם כן מהו ומושב העיר טוב, מכאן אמרו חן מקום על יושביו (סוטה מז א):

But the water is bad. And because of the water, the land causes people to die, and send them to their graves. If so, what is the meaning of, “the city is a good place to live”?¹⁸Above, at the beginning of this verse. From here [we learn] that a place’s charm is perceived by its inhabitants.¹⁹Maseches Sotah 47a. Rabbi Yochonon said that there are three types of charm. 1. The charm a place that is perceived by its inhabitants. 2. The charm a woman holds for her husband. 3. The charm of a newly purchased item for its buyer.

אל מוצא המים. שהיו נובעים משם:

To the source of the water. From where the water flowed.

וישלך שם מלח. והלא מלח דבר המקלקל את המים הוא, אלא נס בתוך נס:

And threw salt there. Now is not salt a thing that spoils water? This was a miracle within a miracle.²⁰This miracle was similar to the one performed by Moshe in Marah. After traveling through the wilderness for three days without water, the Bnei Yisroel finally came to a spring only to find the water undrinkably bitter. Moshe threw a tree whose wood was bitter into the water and the water became sweet and drinkable. See Shemos 15:22-26.—Radak