John Gill Commentary Deuteronomy 1:33

"who went before you in the way, to seek you out a place to pitch your tents in, in fire by night, to show you by what way ye should go, and in the cloud by day." — Deuteronomy 1:33 (ASV)

Who went in the way before you, to search you out a place to
pitch your tents in
For when the cloud was taken up they journeyed, and when that rested, there they pitched their tents; and hereby they were directed to places the most convenient for water for them and their flocks, or for safety from those that might annoy them:

in fire by night, to show you by what way you should go ;
which otherwise they could not have found in dark nights, in which they sometimes travelled, and in, a wilderness where there were no tracks, no beaten path, no common way:

and in a cloud by day ;
to shelter them from the scorching sun, where there were no trees nor hedges to shade them, only rocky crags and hills.