[Machine] Ibn Umar used to grow his beard until the whiteness of his skin could be seen, and he would let it grow between his mustache and his beard.
وَكَانَ ابْنُ عُمَرَ يُحْفِي شَارِبَهُ حَتَّى يُنْظَرَ إِلَى بَيَاضِ الْجِلْدِ، وَيَأْخُذُ هَذَيْنِ، يَعْنِي بَيْنَ الشَّارِبِ وَاللِّحْيَةِ.
The Prophet ﷺ said, "To get the moustaches cut 'short is characteristic of the Fitra."
عَنِ النَّبِيِّ ﷺ قَالَ مِنَ الْفِطْرَةِ قَصُّ الشَّارِبِ
Messenger of Allah ﷺ said, "Five practices are characteristics of the fiṭrah: (1) circumcision, (2) shaving the pubic region, (3) plucking the arm pits, (4) clipping the nails, and (5) cutting the mustaches."
عَنْ أَبِي هُرَيْرَةَ رِوَايَةً الْفِطْرَةُ: «خَمْسٌ» أَوْ «خَمْسٌ مِنَ الْفِطْرَةِ: (١) الْخِتَانُ (٢) وَالاِسْتِحْدَادُ (٣) وَنَتْفُ الإِبْطِ (٤) وَتَقْلِيمُ الأَظْفَارِ (٥) وَقَصُّ الشَّارِبِ۔»