Hadith 21:56
Sahih (Al-Albani)
The above mentioned has also been transmitted by Umm 'Atiyyah through a different chain of narrators. This version has:
we braided her hair in three plaits and placed them behind her back, one plait of the front side and the two side plaits.
حَدَّثَنَا مُحَمَّدُ بْنُ الْمُثَنَّى، حَدَّثَنَا عَبْدُ الأَعْلَى، حَدَّثَنَا هِشَامٌ، عَنْ حَفْصَةَ بِنْتِ سِيرِينَ، عَنْ أُمِّ عَطِيَّةَ، قَالَتْ وَضَفَّرْنَا رَأْسَهَا ثَلاَثَةَ قُرُونٍ ثُمَّ أَلْقَيْنَاهَا خَلْفَهَا مُقَدَّمَ رَأْسِهَا وَقَرْنَيْهَا
Original Reference: Sunan Abi Dawud 3144