Albert Barnes Commentary Numbers 13:21

"So they went up, and spied out the land from the wilderness of Zin unto Rehob, to the entrance of Hamath." — Numbers 13:21 (ASV)

The wilderness of Zin was the northeastern portion of the wilderness of Paran.

Rehob (modern Khurbeh) was probably the Beth-rehob of Judges 18:28, near Dan-Laish; and apparently to the north of it, since it gave its name to a Syrian kingdom (2 Samuel 8:3).

The southern approach to Hamath from the plain of Coele-Syria lay between those two ranges of Lebanon called Libanus and Antilibanus. A low screen of hills connects the northernmost points of these two ranges; and through this screen the Orontes bursts from the upper Coele-Syrian hollow into the open plain of Hamath.