Muwatta Imam Malik Book of The Description of the Prophet ﷺ, Hadith 4
Yahya related to me from Malik from Yahya ibn Said that Said ibn al-Musayyub said, "Ibrahim ﷺ was the first to give hospitality to the guest and the first person to be circumcised and the first person to trim the moustache and the first person to see grey hair. He said, 'O Lord! What is this?' Allah the Blessed, the Exalted, said, 'It is dignity, Ibrahim.' He said, 'Lord, increase me in dignity!' "
Yahya said that he had heard Malik say, "One takes from the moustache until the edge of the lip appears, that is the rim. One does not cut if off completely so that one mutilates oneself."
وَحَدَّثَنِي عَنْ مَالِكٍ، عَنْ يَحْيَى بْنِ سَعِيدٍ، عَنْ سَعِيدِ بْنِ الْمُسَيَّبِ، أَنَّهُ قَالَ كَانَ إِبْرَاهِيمُ ﷺ أَوَّلَ النَّاسِ ضَيَّفَ الضَّيْفَ وَأَوَّلَ النَّاسِ اخْتَتَنَ وَأَوَّلَ النَّاسِ قَصَّ الشَّارِبَ وَأَوَّلَ النَّاسِ رَأَى الشَّيْبَ فَقَالَ يَا رَبِّ مَا هَذَا فَقَالَ اللَّهُ تَبَارَكَ وَتَعَالَى وَقَارٌ يَا إِبْرَاهِيمُ . فَقَالَ رَبِّ زِدْنِي وَقَارًا . قَالَ يَحْيَى وَسَمِعْتُ مَالِكًا يَقُولُ يُؤْخَذُ مِنَ الشَّارِبِ حَتَّى يَبْدُوَ طَرَفُ الشَّفَةِ وَهُوَ الإِطَارُ وَلاَ يَجُزُّهُ فَيُمَثِّلُ بِنَفْسِهِ .