Jami` at-Tirmidhi 2760
جامع الترمذي#2760Da'ifحَدَّثَنَا مُحَمَّدُ بْنُ عُمَرَ بْنِ الْوَلِيدِ الْكِنْدِيُّ الْكُوفِيُّ، حَدَّثَنَا يَحْيَى بْنُ آدَمَ، عَنْ إِسْرَائِيلَ، عَنْ سِمَاكٍ، عَنْ عِكْرِمَةَ، عَنِ ابْنِ عَبَّاسٍ، قَالَ كَانَ النَّبِيُّ صلى الله عليه وسلم يَقُصُّ أَوْ يَأْخُذُ مِنْ شَارِبِهِ وَكَانَ إِبْرَاهِيمُ خَلِيلُ الرَّحْمَنِ يَفْعَلُهُ . قَالَ أَبُو عِيسَى هَذَا حَدِيثٌ حَسَنٌ غَرِيبٌ .
Narrated Ibn 'Abbas:"The Prophet (ﷺ) would pare, or take from his mustache, and Ibrahim Khalilur-Rahman would do it (as well)
Scholarly Authentication
The label above is the grade most of these scholars gave — one dissenting opinion no longer speaks for all of them. If any scholar calls a narration fabricated, that verdict is shown instead, whatever the others say. Each scholar's own wording:
In-book reference: 43:30