Sayyiduna Abdullah bin Busr (may Allah be pleased with him) narrates: I saw the Prophet (peace and blessings be upon him) trimming his moustache closely.
Al-Tabarani recorded it. Its chain contains a narrator, Ya'qub bin Muhammad al-Zuhri, who is da'if (weak), though he has also been declared trustworthy; and a narrator, Mansur bin Isma'il, whom al-Uqayli declared da'if (weak). The remaining narrators of this report are thiqat (trustworthy).
Hadith Referenceمجمع الزوائد ومنبع الفوائد / كتاب اللباس / 8851