The Sufficient (Vol 6) · Hadith 2124 (#Ḥadīth #7)
Chapter 35 | The Beard and Mustache
مُحَمَّدُ بْنُ يَحْيَى عَنِ الْعَمْرَكِيِّ بْنِ عَلِيٍّ عَنْ عَلِيِّ بْنِ جَعْفَرٍ عَنْ أَخِيهِ أَبِي الْحَسَنِ ( عليه السلام ) قَالَ سَأَلْتُهُ عَنْ قَصِّ الشَّارِبِ أَ مِنَ السُّنَّةِ قَالَ نَعَمْ .
7. Muhammad ibn Yahya has narrated from al-‘Amrakiy ibn Ali from Ali ibn Ja‘far from his brother, abu al-Hassan , who has said the following: “I once asked abu al-Hassan , about trimming the mustache; if it is of Sunnah. He (the Imam) said, ‘Yes, it is of Sunnah.”’
Gradings are classical jarḥ-wa-taʿdīl, name-matched to a rijāl index (not individually re-verified).