Sayyiduna Ubayd (may Allah be pleased with him) narrates: The Prophet (peace and blessings be upon him) ordered that the moustache be kept trimmed short.
Al-Tabarani recorded it, and its narrators are the narrators of the Sahih.
Hadith Referenceمجمع الزوائد ومنبع الفوائد / كتاب اللباس / 8843