The pillar of cloud, the ensign of Jehovah's royalty among the Hebrews, and for us one of the most ancient symbols of His grace, is first mentioned in the account of the departure from Egypt. "Jehovah went before them by day in a pillar of cloud, to lead them the way; and by night in a pillar of fire, to give them light." At the passage of the Red Sea this murky cloud removed and came between the host of Israel and their pursuers. In the morning watch "Jehovah looked unto the host of the Egyptians through the pillar of fire and of the cloud, and troubled the host of the Egyptians." On that occasion it followed or represented "the angel of God." There is nowhere any attempt to give a complete account of the symbol. We read of its glory filling the inner shrine and even the holy place. At other times it only hovers above the western end of the tabernacle, marking the situation of the ark. Now and again it moves from that position, and covers the door of the tent of meeting into which Moses has entered. The targums use the term _Shechinah_ to indicate what it was conceived to be--a luminous cloud, the visible manifestation of the Divine presence; and Philo speaks of the fiery appearance of the Deity shining forth from a cloud. But these are glosses on the original descriptions and cannot be altogether harmonised. In one passage only (Isa. iv. 5) do we find a reference which appears to throw any light on the real nature of the symbol. Evidently recalling it, the prophet says, "Jehovah will create over the whole habitation of Mount Zion, and over her assemblies, a cloud and smoke by day, and the shining of a flaming fire by night." To him the cloud is one of smoke rising from a fire which at night sends up tongues of flame; and the reflection of the bright fire on the overhanging cloud resembles a canopy of glory. Ewald's view is that the smoke of the altar which went up in a thick column, visible at a great distance by day, ruddy with flame by night, was the origin of the conception. There are various objections to this theory, which the author of it himself finds difficult to reconcile with many of the statements. At the same time the pillar of cloud does not need to be thought of as in any respect a more Divine symbol than others which were associated with the tabernacle. Certainly the ark of the covenant which Bezaleel made according to the instructions of Moses was, far beyond anything else, the sacred centre around which the whole of the worship gathered, the mysterious emblem of Jehovah's character, the guarantee of His presence with Israel. It was from the space above the mercy-seat, as we have seen, that the Voice proceeded, not from the pillar of cloud. The sanctity of the ark was so great that it was never exposed to the view of the people, nor even of the Levites who were set apart to carry it. The cloud, on the other hand, was seen by all, and had its principal function in showing where the ark was in the camp or on the march.