Calvin's Commentaries, Vol. 6: Harmony of the Law, Part IV, tr. by John King, [1847-50], at sacred-texts.com
36. And when the cloud was taken up from over the tabernacle, the children of Israel went onward in all their journeys:
36. Quum recederet nubes a tabernaculo, proficiscebantur filii Israel in cunctis profectionibus suis:
37. But if the cloud were not taken up, then they journeyed not till the day that it was taken up.
37. Quod si non recederet nubes, non proficiscebantur usque ad diem qua recedebat.
38. For the cloud of the Lord was upon the tabernacle by day, and fire was on it by night, in the sight of all the house of Israel, throughout all their journeys.
38. Quia nubes Jehovae erat super tabernaculum interdiu, ignis vero noctu in eo, coram oculis totius domus Israel, in cunctis profectionibus eorum.
38. For the cloud of the Lord was on the tabernacle. Moses more distinctly explains what he had said generally respecting the cloud, viz., that by night a fiery column appeared, because the cloud would not have been visible amidst the darkness. A second explanation is also added, that this did not happen once or twice only, but “in all their journeys;” so that they were never without a sight of the cloud, which might be a witness of God’s presence, whether, being settled on the tabernacle, it commanded them to rest, or, by its ascension, gave them the sign for removing the camp. Now, the equability of this proceeding, in all the variety of times and marches, did not a little conduce to certainty; for, if the cloud had daily accomplished the same course, this very regularity would have obscured the power’ of God; but when for a whole year it did not move, and then frequently proceeded to a new place, and now by its. guidance pointed out a longer journey, now a shorter one, by this very diversity the paternal care of God, who was never unmindful of His people, more conspicuously manifested itself.