Matthew Poole and continuators on Numbers 13:21

21 So they went up, and searched the land, from the wilderness of Zin , unto Rehob, as men come to Hamath .

In the south of Canaan, Numb. 34. 3. Jos. 15. 3. differing from the wilderness of Sin, which was nigh unto Egypt, Exod. 16. 1.

(i. e.) From the South they passed through the whole land even to the Northern parts of it, Rehob, a city in the North-west part, Ios. 19. 28. Iudg. 1. 31. and Hemath, a city in the North-east part, Ios. 19. 35. Ezek. 47. 17. And that they might more expeditiously and securely perform this office it is probable, that they divided themselves into several small parties, and informed themselves not onely by their eye, but also by their ear and the information of persons of whom they enquired about the nature and condition of their land.