مِشْكَاةُ الْمَصَابِيحِ
Mishkat al-Masabih 4408
Clothing
Sandals - Section 1
وَعَنْ أَنَسٍ قَالَ: إِنَّ نَعْلَ النَّبِيِّ صَلَّى الله عَلَيْهِ وَسلم كَانَ لَهَا قبالان
Anas said the Prophet’s sandal had two thongs. Bukhari transmitted it.
Mishkat al-Masabih, 4408صَحِيح (الألباني)