The same applies to the fire produced in a lamp’s wick when it is placed in a fire, or when wood is placed in a fire. The fire first transforms the material—oil or wood—so that the surrounding air grows hot and turns into fire. This transformation occurs only after some of the material has been lost.

The same applies to air that fans a fire, as when wind blows and the fire blazes in the wood, or when bellows or the like are used to blow air. The air being blown continues to kindle the fire because the material sustaining it, such as wood and charcoal, is capable of turning into fire, and because the strong movement of the air carries the fire to material capable of receiving it. The air near the fire may also be transformed, for flame is air that has turned into fire, like the flame in a lamp’s wick. Thus, when it is extinguished, it becomes smoke: air mixed with fire, just as vapour is air mixed with water, and dust is air mixed with earth.

Vapour may also be called smoke. An instance of this is the saying of the Most High:

“Then He turned towards the heaven while it was smoke.”

The Quran commentators explained this as water vapour, as stated in the transmitted reports:

“Allah created the heavens from water vapour.”

This is the smoke in question. Smoke is air mixed with something hot. It may contain no water, in which case it is simply smoke; or it may contain water, in which case it is both smoke and vapour, like the vapour rising from a cooking pot. Smoke may also be called vapour. Thus, someone who fumigates himself with fragrant incense is said to have tabakhkhara (“used vapour”), even though no moisture is present; rather, the fragrant smoke is called vapour.

Al-Jawharī said: “Water vapour is what rises from water like smoke. Bakhūr, pronounced with a short a in the first syllable, is what is used for fumigation.” However, the air turns into fire only