Perhaps I shall be laughed at if I distinguish between the wilderness of Judah and the wilderness of Judea. And formerly such a distinction did deserve laughter; but when the name of Idumea, as I have shewed, swallowed up a great part of Judea, then it was not only to be borne with, but necessary also, to distinguish between the wilderness of Judah, of which Joshua 15:61, and the title of Psalm 63, and the wilderness of Judea where John baptized.
The title of that Psalm in the original Hebrew is thus, "A Psalm of David when he was in the desert of Judah." But the Greek interpreters render it, "A Psalm of David when he was in the wilderness of Idumea." And the Vulgar, "A Psalm of David when he was in the desert of Idumea": acting the part of no good interpreters, but of no ill paraphrasts. So Jeremiah 9:26; "Upon Idumea, and upon Edom."
If you ask where David was when he composed that Psalm, it is answered (1 Sam 24:1), "In the wilderness of En-gedi": and if you search further for the precise place, it was there where the castle Masada was afterward built. For I doubt not at all, that that place, as Josephus describes it, was the same with "the rocks of the wild goats." [1 Sam 24:3]
I appeal here to the maps and their authors, in whom 'En-gedi' and 'Masada' (and 'Lot's cave') are placed not very far from the utmost north cost of Asphaltites: let them say whether Idumea stretched out itself so far. If not, let them correct the interpreters whom we have named; and thought it be so, they might show by what authority they place those places there, and let them friendly correct me putting them far elsewhere.