General meaning:
A man drank wine during the lifetime of the Prophet ﷺ, so the Prophet struck him with a palm-branch about forty lashes.
Abu Bakr d. 13 AH administered to a wine-drinker in his caliphate the same punishment that the Prophet ﷺ had imposed.
When ʿUmar became caliph, the conquests expanded, Muslims mixed with other peoples, and the incidence of drinking increased. As was his practice in important and ijtihād-based matters, he consulted the scholarly Companions about the penalty that would deter them. ʿAbd al-Raḥmān ibn ʿAwf said, “Make it like the lightest of the fixed punishments—eighty lashes,” referring to the punishment for slander. ʿUmar therefore set it at eighty.

Lessons derived from the ḥadith:

1. The prescribed punishment (ḥadd) for wine drinking is established, and this is the view of the vast majority of scholars.
2. In the Prophet’s time it was about forty lashes, and Abu Bakr continued that practice.
3. After consulting the Companions, ʿUmar raised it to eighty lashes.
4. Exercising ijtihād in legal questions and consulting scholars is the habit of those who seek the truth, whereas autocracy is the way of the self-admiring and arrogant who refuse to face realities.

Scholarly disagreement:
The jurists have differed: Is the ḥadd for wine eighty lashes or forty? Is anything between forty and eighty merely a discretionary punishment (taʿzīr) that the ruler may impose if he sees fit, otherwise limiting it to forty?
Imams Aḥmad, Mālik, Abū Ḥanīfah, al-Thawrī, and many who followed them held that the ḥadd is eighty lashes, citing the consensus of the Companions: when ʿUmar consulted them, ʿAbd al-Raḥmān ibn ʿAwf said, “Make it the lightest of the fixed punishments—eighty,” and ʿUmar adopted that number.
Al-Shāfiʿī maintained that the ḥadd is forty lashes. This is also one narration from Imām Aḥmad preferred by a group of his students, among them Abū Bakr, Shaykh al-Islām Ibn Taymiyyah, Ibn al-Qayyim, and our teacher ʿAbd al-Raḥmān ibn Saʿdī—may Allah have mercy on them all.
Shaykh al-Islām Ibn Taymiyyah, as quoted in al-Ikhtiyārāt, said: “The correct view regarding the ḥadd for wine—one of the two narrations and the view that accords with that of al-Shāfiʿī and others—is that the increase from forty to eighty is not universally obligatory; rather, it is left to the ijtihād of the ruler, just as we allow him to exercise judgment regarding the manner of striking.”