Koran, the tradition (Sunna ) and consensus about the fermented beverages.
The words revealed in the Qur'an are supplemented by Tradition (Sunna), the second authority taken from the words (hadîth) of the Prophet and his Companions. Several traditions or schools of thought will emerge depending on whether or not it is accepted that the authority of the Prophet was communicated (transmitted) to the wider circle of his Companions (the sahaha witnesses of his life), his parents, the followers in Madinah during his lifetime or after his death. This complex issue has divided Muslims, particularly Sunni and Shia legal schools (e.g. Madhhabs). The nature of the Authority, its constitution, its transmission are at issue. The idjmâ (unanimity, consensus adopted by the Doctors of Islam) is one of the sources of Muslim law, after the Koran and the Sunna. Legal schools give it a more or less important place. A rule of law can in no way contradict the Koran or the Sunna.
- The Sunnites admit the rule of consensus, invoking the hadith " My community does not agree on a mistake (var. confusion, misbelief) »;
- The Malekism recognizes only the idjmâ of the companions of Mohammed and of those who followed him to Medina, invoking the hadith « Belief goes back to Medina like a snake crawls to its hole »;
- Hanbalites only recognize the idjmâ of Muhammad's Companions
- The Shi'ites admit the collective opinion of the only descendants of Muhammad by blood or marriage.
- The Kharijites and Mu'tazilites rejected the principle of idjmâ. They refer to Qur'an and Sunnah only.
While some argue and persuade the believer of the taint and delusion that are implied by the consumption of alcoholic beverages, others condemn not only the consumption but also their production, trade, and the direct or indirect (profits) of the alcohol as haram, that is illegal and therefore prohibited from a religious standpoint. Anyone tempted to deny the prohibition of alcohol, regardless the reason (ignorance, delusion, deception) is treated as an apostate and someone who abjures one of the foundations of Islam.
Here are some hadiths which leave no doubt. The word "wine" includes all alcoholic beverages (khamr means "what can intoxicate [somebody]")
This hadith is very accurate: « `Umar stood up on the pulpit and said, "Now then, prohibition of alcoholic drinks have been revealed, and these drinks are prepared from five things : grapes, dates, honey, wheat or barley. An alcoholic drink is what disturbs the mind. », narrated by Ibn 'Umar.
And this one about the mead : « Allah's Messenger was asked about Al-Bit, a liquor prepared from honey which the Yemenites used to drink. Allah's Messenger said, "All drinks that intoxicate are unlawful (to drink)" », narrated by 'Aisha.
« Whatever a lot of it intoxicates, a little of it is unlawful [haram] », narrated by Al Bukhari and Muslim.
« Allah's Messenger cursed ten people in connection with wine: the wine-presser, the one who has it pressed, the one who drinks it, the one who conveys it, the one to whom it is conveyed, the one who serves it, the one who sells it, the one who benefits from the price paid for it, the one who buys it, and the one for whom it is bought. », narrated by Anas Ibn Malik (Hadith - Al-Tirmidhi #2776).
« Don't drink khamr for is the key of all evil » narrated by Ibn Hanbal and Ibn Maja.
« He who drinks wine in this world and dies while he is addicted to it, not having repented, will not be given a drink in the Hereafter. », narrated by Al Bukhari who refers to the promises of the paradise in the Qur'an « Is the description of Paradise, which the righteous are promised, wherein are rivers of water unaltered, rivers of milk the taste of which never changes, rivers of wine delicious to those who drink, and rivers of purified honey ... » (sourate 47, VII, 15).
« They will be given to drink [pure] wine [which was] sealed » (surah 83, 25). But it is never said whether this pure wine is a mundane drink or a metaphor of pure knowledge.
« Whoever believes in Allah and the Last Day, should not drink alcohol », rapporté par El-Bukhari.
« Cursed is the one who drinks, buys, sells wine or prompts others to drink it » rapporté par Abu Daoud, Ibn Maja et Ibn Hanbal.
« Cursed is the one who gives the wine for free, or who enjoy the profit from its sale » narrated by Tirmidhi.
« The prayer of one who drinks wine will not be agreed by Allah ».
« Drinking wine is incompatible with faith », hadith narrated by Al Bukhari.
« Il est déconseillé de l’employer comme remède », rapporté par Muslim et Ibn Hanbal.
« « The Prophet said: "Allah has sent down both the malady and its remedy. For every disease He has created a cure. So seek medical treatment, but never with something the use of which Allah has prohibited. », reported by Abu ad-Darda. Therefore, the forbiden alcohol cannot be regarded even as a medicine given to the sick, even in exceptional circumstances.
 The Hanafi school, founded in Iraq by Imam Abu Hanifa (d. 767), a broad mind, is the one which makes most appeal to human reason. The two other schools of Imam Malik (d. 795) and Imam al-Shafii (d. 820) put forward the notion of consensus, even incorporating extra-Islamic customs such as, for example, the customary rights of Maghreb (urf ) adopted by the Malekism. Finally, the school of Imam Ahmad ibn Hanbal (d. 855) opts for a rigorous view modeled on the Prophet's teaching (Sunna/Tradition).