Mishkat al-Masabih 22 Clothing كتاب اللباس 110

وَعَنِ ابْنِ عُمَرَ قَالَ: قَالَ رَسُولُ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ: ” خَالِفُوا الْمُشْرِكِينَ: أَوْفِرُوا اللِّحَى وَأَحْفُوا الشَّوَارِبَ ” . وَفِي رِوَايَةٍ: «أنهكوا الشَّوَارِب وأعفوا اللحى»

Ibn ‘Umar reported God’s messenger as saying, “Do the opposite of what the polytheists do ; let the beard grow long and clip the moustache.” A version has, “Cut the moustache down and leave the beard.” (Bukhari and Muslim.)