Sunan Ibn Majah, Hadith 3581 ⓘ
It was narrated from Ibn ‘Umar: “The wives of the Prophet were allowed to let their hems hang down, so they used to come to us and we would measure one forearms length for them with a reed.”
حَدَّثَنَا أَبُو بَكْرٍ، حَدَّثَنَا عَبْدُ الرَّحْمَنِ بْنُ مَهْدِيٍّ، عَنْ سُفْيَانَ، عَنْ زَيْدٍ الْعَمِّيِّ، عَنْ أَبِي الصِّدِّيقِ النَّاجِيِّ، عَنِ ابْنِ عُمَرَ، أَنَّ أَزْوَاجَ النَّبِيِّ، ـ صلى الله عليه وسلم ـ رُخِّصَ لَهُنَّ فِي الذَّيْلِ ذِرَاعًا فَكُنَّ يَأْتِيَنَّا فَنَذْرَعُ لَهُنَّ بِالْقَصَبِ ذِرَاعًا .
also referenced under: Book 32, Hadith 3712 (In-Book) & Volume 4, Book 32, Hadith 3581 (DarusSalam)