It is narrated from Sayyiduna Abdullah bin Abbas (may Allah be pleased with them both) that the Prophet (peace and blessings be upon him) used to trim his moustache, and Sayyiduna Ibrahim, the Khalil (intimate friend) of Allah, also used to trim his moustache.
Hadith Referenceالمعجم الكبير للطبراني / باب العين / 11675