This is another article in the chapter Probable Enormities from the classical manual on Sharia called Reliance of the Traveller. The articles are posted one by one in the order they are given in the book.
NOT TRIMMING ONE’S MUSTACHE
p75.16 The Prophet (Allah bless him and give him peace) said:
(1) “He who does not trim his mustache [def: e4.1(2)] is not one of us.”
(2) “Be different from the Zoroastrians:
grow your beards and trim your mustaches.”