Numbers 10:34

And the cloud of the Lord [was] upon them by day
Not only upon the tabernacle, and upon the ark particularly, but it spread itself in journeying over the whole body of the people, and therefore said to be a covering to them from the heat of the sun, ( Psalms 105:39 ) ; as well as it was a guide unto them, and a token of the divine Presence with them, see ( Isaiah 4:5 ) ;

when they went out of the camp;
or out of the place of their encampment, when they removed from Sinai; and appears from, hence that it was in the daytime.