Regarding it, He says: “There will be no ill effects in it, nor will they become intoxicated by it” [al-Saffat]. This conclusion is unavoidable, for we have a Sunnah from the Prophet—peace and blessings be upon him—establishing that it is not physically impure.
Moreover, the drink of the people of Paradise is not limited to wine. There are also rivers of water, milk, and honey, all of which they drink from. Can it then be said that the water, milk, and honey of this world are impure by the implied meaning of this verse?
If it is asked: How can you differ from the majority?
The answer is that Allah Most High has commanded that, in cases of disagreement, recourse be made to the Quran and the Sunnah, without regard to the numerical strength of either side. Upon referring back to the Quran and the Sunnah, it becomes clear to the thoughtful observer that neither contains any evidence that wine is physically impure. If no evidence establishes this, then the basic presumption is purity. Moreover, we have already presented proofs indicating that it is physically pure.
If it is converted into vinegar, or if liquid oil becomes impure, it does not become pure, …
His statement, “If it is converted into vinegar,” refers to wine. Converting it into vinegar means adding to it something, such as a fermented drink or otherwise, that removes its intoxicating potency, or treating it in some way that removes that potency.
The well-known position of the school is that, if it is converted into vinegar, it does not become pure, even if its intoxicating potency has disappeared. There is no difference between the wine of a vinegar-maker and any other wine, although some scholars made an exception for the wine of a vinegar-maker and held that it may be converted into vinegar (1), since it constitutes all of his wealth, and preventing him from converting it into vinegar would ruin his property. The correct view, however, is that there is no difference: once wine has become wine, it must be poured out, and it is not permissible to keep it for the purpose of converting it into vinegar. This differs from the case in which it turns into vinegar on its own, for then it becomes pure and lawful.