Sahih Muslim Book - 2, Hadith - 599

حَدَّثَنَا يَحْيَى بْنُ يَحْيَى وَقُتَيْبَةُ بْنُ سَعِيدٍ كِلَاهُمَا عَنْ جَعْفَرٍ قَالَ يَحْيَى أَخْبَرَنَا جَعْفَرُ بْنُ سُلَيْمَانَ عَنْ أَبِي عِمْرَانَ الْجَوْنِيِّ عَنْ أَنَسِ بْنِ مَالِكٍ قَالَ قَالَ أَنَسٌ وُقِّتَ لَنَا فِي قَصِّ الشَّارِبِ وَتَقْلِيمِ الْأَظْفَارِ وَنَتْفِ الْإِبِطِ وَحَلْقِ الْعَانَةِ أَنْ لَا نَتْرُكَ أَكْثَرَ مِنْ أَرْبَعِينَ لَيْلَةً

It was narrated that Anas bin Malik said: "Anas said: 'A time limit was set for us for trimming the moustache, clipping the nails, plucking the armpit hairs and shaving the pubes: that was not to be left for more than forty days."'