Beside the historical sense of this passage, let the reader not overlook the spiritual. If he consults the Prophet, he will discover that the LORD himself, is both the pillar of fire and the cloud. Isaiah 27:3; Isaiah 27:3.
Related Commentaries of Numbers 9:15
Numbers 9:15-16
15 And on the day that the tabernacle was reared up the cloud covered the tabernacle, namely, the tent of the testimony: and at even there was upon the tabernacle as it were the appearance of fire, until the morning.
16 So it was alway: the cloud covered it by day, and the appearance of fire by night.