Radak (3): This is more common than the other three [who must thank Hashem], for people often go from land to land for business, and pass through Midbaros. Hashem will gather them from where they went.

Rashi: All who traverse Midbaros must thank, for sometimes they get lost and are hungry and thirsty (verse 5).

Radak: This is one of the afflictions that comes in the Midbar. Due to the abundance of sand, wind blows it and the roads are covered, and people cannot find the road to the city of their destination.

Malbim: When they were exiled, they went via the Midbar, and could not find the city of their destination.

Malbim: It is more desolate than a Midbar.