The pillar of fire (Hebrew: עמוד אש, romanized: ‘ammuḏ ’ēš) and pillar of cloud (Hebrew: עמוד ענן, romanized: ‘ammūḏ ‘ānān) are a dual theophany (manifestation of God) described in various places in the first five books of the Hebrew Bible. The pillars are said to have guided the Israelites through the desert during the Exodus from Egypt. The pillar of cloud provided a visible guide for the Israelites during the day, while the pillar of fire lit their way by night.

The pillars of cloud and fire are first mentioned in Exodus 13, shortly after Moses leads the Israelites out of their captivity in Egypt. The narrative states that the pillar of cloud went ahead of them by day to guide their way, and the pillar of fire by night, to give them light.

The Pharaoh, however, brings an army in pursuit of the Israelites and catches up to them at their encampment beside the Red Sea. The pillar of cloud intervenes to keep the army from approaching during the night; it positions itself behind the Israelites, casting light upon their camp while leaving the Egyptian army in darkness. Then Moses parts the Red Sea, and the Israelites cross the dry riverbed. The Egyptians follow them, but God looks down upon them from the pillar of fire and cloud and throws their forces into confusion.

When the Israelites arrive at Mount Sinai, the cloud covers the mountain, and Moses enters into it to receive the commandments. To the observers below, the cloud appears as a "devouring fire" on top of the mountain. Later, after the Tabernacle (or "tent of meeting") has been constructed, the pillar of cloud descends to the entrance of the tent, where God talks with Moses "face to face".

From this point on, the narrative states that whenever the Israelites made camp, the cloud would descend and cover the Tabernacle (looking like fire by night). When it lifted again, they would set out on the next stage of the journey, with the cloud leading the way. Sometimes the cloud would remain a long time over the Tabernacle; sometimes only from evening until morning. Whether it lingered for "two days, or a month, or a year", the Israelites would not break camp until the cloud lifted up and moved on.

Elsewhere in the Bible, there are references to the pillars of cloud and fire in the Book of Psalms, and the Book of Nehemiah. The theme is built upon in the Book of Isaiah; in chapter 4, the prophet describes his vision of the holy city of Zion in the post-apocalyptic era, and says that the city will be canopied by a cloud of smoke by day and a fire by night. There is also reference to a fire inside a cloud in the first chapter of the Book of Ezekiel, and this chapter has been traditionally linked to the story of the revelation at Sinai.

Christian commentators have generally considered that the narrative describes not two pillars (one of cloud and one of fire), but a single pillar which changes its appearance by day or by night. Carl Friedrich Keil, for example, wrote: "[W]e have to imagine the cloud as the covering of the fire, so that by day it appeared as a dark cloud in contrast with the light of the sun, but by night as a fiery splendour." As evidence for this, Keil cites Exodus 40:38, and interprets that the fire was in the cloud (a rendering followed by most modern translations). He also points to Exodus 14:20, which suggests that the cloud had a bright side and a dark side, being able to simultaneously illuminate the Israelite camp while spreading darkness over the Egyptians. This point is explicitly stated in an ancient Jewish version of the text, Targum Pseudo-Jonathan, which reads: "a cloud, one half of which was light and one half darkness."

On the other hand, the medieval Jewish commentator Nachmanides held that there were two pillars, and that in the passage under discussion, the pillar of cloud interposed itself between the pillar of fire and the Egyptian army, thus preventing the light of the fire from reaching them. Rashi, likewise, believed that there were two pillars, writing that "before one set, the other rose".