The Book of Adornment
48/116. Chapter:
Description of the Sandals of the Messenger of Allah [SAW]
Sunan an-Nasai
أَخْبَرَنَا عَمْرُو بْنُ عَلِيٍّ، قَالَ حَدَّثَنَا صَفْوَانُ بْنُ عِيسَى، قَالَ حَدَّثَنَا هِشَامٌ، عَنْ مُحَمَّدٍ، عَنْ عَمْرِو بْنِ أَوْسٍ، قَالَ كَانَ لِنَعْلِ رَسُولِ اللَّهِ صلى الله عليه وسلم قِبَالاَنِ .
It was narrated that 'Amr bin Aws said: "The sandals of the Messenger of Allah [SAW] had two straps."
Reference : Sunan an-Nasa'i 5368In-book reference : Book 48, Hadith 329English translation : Vol. 6, Book 48, Hadith 5370