"The city of Salt" is not mentioned elsewhere, but was no doubt connected with "the valley of salt" 2 Samuel 8:13. The name itself, and the mention of En-gedi (Genesis 14:7 note) suggest that its site must be looked for near the Dead Sea.

The city of Salt - Or of Melach. This city was somewhere in the vicinity of the lake Asphaltites, the waters of which are the saltest perhaps in the world. The whole country abounds with salt: see the note on Genesis 19:25. Some suppose that it is the same as Zoar, the place to which Lot escaped after the destruction of Sodom and Gomorrah.

En-gedi - The well of the kid: it was situated between Jericho and the lake of Sodom or Dead Sea.

And Nibshan,.... Of Nibshan no mention is made elsewhere:

and the city of Salt some take to be Zoar, so called because near the salt sea, or where Lot's wife was turned into a pillar of salt, Genesis 19:22; but rather this city might be so called, because salt was made here.

and Engedi, or Engaddi, is a well known place, near the salt sea; See Gill on Ezekiel 47:10. Jerom says (y), there was a very large village of Jews in his time called Engaddi, near the dead sea, from whence comes the opobalsam; the same place is called Hazazontamar, from the palm trees which grew there, 2 Chronicles 20:2. It was famous for vineyards also, Sol 1:14; it lay, according to Josephus (z), three hundred furlongs or about forty miles from Jerusalem:

six cities with their villages; the sum total agrees with the particulars.

(y) De loc. Heb. fol. 91. B. (z) Antiqu. l. 9. c. 1. sect. 2.

Nibsan, also unknown. The city of salt (salt town), in which the Edomites sustained repeated defeats (2 Samuel 8:13; Psalm 60:2; 2 Kings 14:7; 1 Chronicles 18:12; 2 Chronicles 25:11), was no doubt at the southern end of the Dead Sea, in the Salt Valley (Rob. ii. p. 483). Engedi, on the Dead Sea (Ezekiel 47:10), to which David also fled to escape from Saul (1 Samuel 24:1.), according to the Onom. (s. v. Engaddi) a vicus praegrandis, the present Ain-Jidi, a spring upon a shelf of the high rocky coast on the west of the Dead Sea, with ruins of different ancient buildings (see Seetzen, ii. pp. 227-8; Rob. ii. pp. 214ff.; Lynch, pp. 178-9, 199, 200).

And Nibshan, and the {l} city of Salt, and Engedi; six cities with their villages.

(l) Of this city the salt sea has it's name.

15:62 City of salt - So called either from the salt sea, which was near it; or from the salt which was made in, or about it.

15:20-63 Here is a list of the cities of Judah. But we do not here find Bethlehem, afterwards the city of David, and ennobled by the birth of our Lord Jesus in it. That city, which, at the best, was but little among the thousands of Judah, Mic 5:2, except that it was thus honoured, was now so little as not to be accounted one of the cities.