Nahy (prohibition, in usul al-fiqh)

Nahy, in the lexicon, is the opposite of command: to "forbid someone a thing" is to deter him from it. In the usulis' usage it is demanding cessation from an act from a position of superiority, and they elaborate its rules: its form, whether it conveys permanence, immediacy, tahrim and invalidity, and the other senses in which its form is used. ^{1 2}

In the lexicon, nahy is the opposite of amr: "he forbade him the thing" means he deterred him from it, and "God forbade such-and-such" means He made it unlawful. In the technical sense the usulis give it several definitions, among them: demanding cessation from an act from a position of superiority. ¹

Command (amr). Among its lexical meanings is requesting an act, and the jurists use it in that sense; the relation between command and prohibition is one of opposition. ¹

The majority hold that prohibition has a form dedicated to it that signifies it when stripped of contexts — the saying "la taf'al" (do not do). Abu al-Hasan al-Ash'ari and those who follow him say it has no form peculiar to it. ²

Conveying permanence and repetition. The usulis differ over whether prohibition conveys permanence and repetition: a group held categorically that the absolute prohibition requires permanence and repetition, while others hold other views in the matter. ² Conveying immediacy. They differ over whether prohibition requires cessation at once, some holding it conveys immediacy and others dissenting. ² Conveying tahrim. Most scholars hold that the absolute prohibition conveys criminalization (tahrim); some say it is suspended, conveying neither criminalization nor anything else without a proof; and others say it is really for purification (tanzih) not tahrim, that being certain, so it is carried on that and not on tahrim without evidence. The majority's proof is surah al-Hashr verse 7, and that the Companions referred criminalization back to the mere prohibition. ^{2 3} Conveying invalidity. The usulis and jurists differ over whether the absolute prohibition conveys invalidity: most scholars hold that it conveys it in general, then they disagreed. The Malikis and Hanbalis say it conveys invalidity absolutely unless an evidence points to the contrary — they have detail on this. The Hanafis and Shafi'is divide prohibition into a kind that returns to the substance of the prohibited thing, like the sale of blood, carrion or pork, or to a pillar or condition of the contract, like the sale of malaqih — this kind never takes effect, by agreement; a kind that returns to a meaning adjacent to the prohibited thing, not to the thing itself in origin or attribute, like selling when the call to the Friday prayer begins; and a kind that returns to a meaning attached to the prohibited as an attribute — the prohibition of a thing for its necessary attribute — which is the point of dispute between the Hanafis and the Shafi'is. ^{3 4}

The form of prohibition is used in senses other than criminalization: dislike, as in surah al-Baqarah verse 267; supplication, as in surah Al Imran verse 8; guidance, as in surah al-Ma'idah verse 101; belittling the thing forbidden, as in surah Ta-Ha verse 131; despairing, as in surah al-Tawbah verse 66; and declaring the consequence, as in surah Ibrahim verse 42. ^{3 4}

Forbidding wrong is demanding cessation from an act in which there is no divine pleasure; it is among the collective duties that the Muslims must carry out — they all sin if they all abandon it, and the burden falls from the rest when some perform it — on surah Al Imran verse 104; the detail is in the entry on commanding right and forbidding wrong. ⁴