أَخْبَرَنَا عَلِيُّ بْنُ حُجْرٍ، قَالَ أَنْبَأَنَا عَبِيدَةُ بْنُ حُمَيْدٍ، عَنْ يُوسُفَ بْنِ صُهَيْبٍ، عَنْ حَبِيبِ بْنِ يَسَارٍ، عَنْ زَيْدِ بْنِ أَرْقَمَ، قَالَ قَالَ رَسُولُ اللَّهِ صلى الله عليه وسلم ‏"‏ مَنْ لَمْ يَأْخُذْ شَارِبَهُ فَلَيْسَ مِنَّا ‏"‏ ‏.‏
Translation
It was narrated that Zaid bin Arqam said

"The Messenger of Allah (ﷺ) said: 'Whoever does not trim his mustache, he is not from one of us.'"

Comment

Hadith Text & Reference

"The Messenger of Allah (ﷺ) said: 'Whoever does not trim his mustache, he is not from one of us.'" (Sunan an-Nasa'i 13)

Legal Ruling (Hukm)

This hadith establishes the obligation (wujub) of trimming the mustache. The phrase "he is not from one of us" indicates strong disapproval and that neglecting this practice distances one from the complete following of the Prophet's way.

Definition of Trimming

Scholars differ on the extent: the Shafi'i and Hanbali schools hold that the mustache should be shortened to the edge of the lip. The Hanafi school states it should be trimmed so that it does not cover the upper lip or interfere with eating and drinking.

Wisdom & Benefits

Trimming promotes cleanliness (taharah) and neatness, preventing food and drink from being contaminated. It distinguishes Muslims in appearance and embodies the comprehensive nature of Islamic teachings covering all aspects of life.

Companion with Sunnah

This practice is from the fitrah (natural disposition) and is to be accompanied by other sunnah acts like trimming nails, removing armpit and pubic hair, and circumcision, completing the Muslim's adherence to prophetic guidance in personal grooming.