The First: Like other natural causes, fire does not act according to its own wishes and nature, blindly, but performs a duty under a command. Thus it did not burn Abraham (Peace be upon him), because it was commanded not to burn him.
The Second: There is a degree of heat which burns through its coldness. That is, it has an effect like burning. Through the word, Be cool!,33 Almighty God is saying to the coldness: "Do not burn him with your coldness, the same as your heat!" That is to say, through its coldness, fire at that degree has an effect like burning. It is both fire and cold. In fact, in natural science there is a degree of fire, the state of 'white heat,' the heat of which does not spread to its surroundings. It attracts the heat around it to itself and with this cold, freezes surrounding liquids such as water, in effect burning them through its cold. Thus, intense cold is a category of fire which burns through its cold. In which case, this intense cold is surely a part of Hell, for it contains all the degrees and sorts of fire.
The Third: Just as there is an immaterial substance like belief which counters the effects of Hell-fire and affords protection against it, the armour of Islam, so there is a physical substance which protects against the effects of worldly fire. For as is required by the Name of All-Wise, this world is the abode of wisdom, and Almighty God carries out His works under the veil of causes. Therefore, the fire burnt neither Abraham's body, nor his garments; He imbued them with a state which resisted fire. Thus, by this allusion, the verse is in effect saying: "O nation of Abraham! Resemble Abraham, so that your garments may be your armour against fire, your greatest enemy both here and there. Clothe your spirit in belief in God, and it will be your armour against Hell-fire. Moreover, there are certain substances which Almighty God has hidden in the earth for you which will protect you from the evils of fire. Search for them, extract them, and clothe yourselves in them!" Thus, one of man's important discoveries and a step in his progress was his finding a substance which fire does not burn; and he clothed himself in garments resistant to fire. So see how elevated, subtle, and fine a garment this verse weaves on the loom of Hanlfan Musliman, which will not be rent in all eternity.
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33. One Qur'anic commentary states: If He had not said: Be cool!, it would have burnt him with its coldness. [See, for example, Ibn Hanbal, al-Zuhd, 101.— Tr.]