Hadith 17:198
Marwan ibn Mu'awiyah narrated to us, from Abd al-Aziz ibn Umar, who said: Umar ibn Abd al-Aziz was asked, "What is the Sunnah regarding the excess of the mustache?" He said: "It is to be trimmed until the border appears, and the excess of the two sides of the mustache is to be cut."
حدثنا مروان بن معاوية عن عبد العزيز بن عمر قال سئل عمر بن عبد العزيز ما السنة في فضل الشارب قال يقص حتى يبدو الإطار ويقطع فضل الشاربين