Smith's Bible Dictionary (1863)
The pillar of cloud by day and of fire by night that God caused to pass before the camp of the children of Israel when in the wilderness. The cloud, which became a pillar when the host moved, seems to have rested at other times on the tabernacle, whence god is said to have “come down in the pillar.” (Numbers 12:5; Exodus 33:9,10) It preceded the host, apparently resting on the ark which led the way. (Exodus 13:21; 40:36) etc.; Numb 9:15-23;
10:34
Hastings' Dictionary of the Bible (1898)
CLOUD, PILLAR OF. When the people of Israel commenced their march through the wilderness, God caused a cloud resembling a pillar to pass before the camp. In the day-time it was like a cloud, dark and heavy, and in the night bright and shining like fire. It also served as a signal for rest or motion. Num 9:17-23.