‘Ali said that at the battle for Khaibar God’s Messenger forbade the temporary marriage (mut’a) of women, and eating the flesh of domestic asses. (Bukhari and Muslim.)
Prohibition of Mut'a Marriage and Donkey Flesh
This narration from the esteemed Companion 'Ali ibn Abi Talib (may God be pleased with him) establishes two significant prohibitions enacted during the Battle of Khaybar. The first concerns the practice of temporary marriage (mut'at an-nisa'), which was permitted in early Islam during times of necessity but was subsequently abrogated and permanently forbidden.
The scholars of jurisprudence explain that this abrogation came to establish the noble and permanent nature of the marital contract in Islam, which is founded upon compassion, mercy, and stability, not transient pleasure. The second prohibition concerns the flesh of domesticated donkeys, which the divine law has forbidden due to its impurity and harm.
Legal Ruling and Wisdom
The consensus of the Sunni schools of law is that temporary marriage is absolutely forbidden and constitutes a major sin. This ruling protects lineage, honors women, and establishes families upon a foundation of mutual responsibility and permanence, in accordance with the verse: "And they have taken from you a strong covenant" (Quran 4:21).
As for the prohibition of domestic donkey flesh, it is considered unlawful (haram) based on this and other authentic narrations. The wisdom behind this is attributed to reasons of health and spiritual purity, distinguishing what is wholesome (tayyib) from what is impure (khabith).