Hadith on Dress: The Sunnah of trimming the moustache and letting the beard grow

Ibn Umar reported: The Prophet, peace be upon him, said, “Trim your moustaches and grow your beards.”
[Sahih Muslim, Book 2, Number 498]

عَنْ ابْنِ عُمَرَ  عَنْ النَّبِيِّ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ قَالَ أَحْفُوا الشَّوَارِبَ وَأَعْفُوا اللِّحَى

صحيح مسلم كتاب الطهارة باب خصال الفطرة