Sunan Ibn Majah, Hadith 1039 ⓘ
It was narrated that ‘Abdullah said: “We saw the Messenger of Allah performing prayer wearing sandals and leather slippers.”
حَدَّثَنَا عَلِيُّ بْنُ مُحَمَّدٍ، حَدَّثَنَا يَحْيَى بْنُ آدَمَ، حَدَّثَنَا زُهَيْرٌ، عَنْ أَبِي إِسْحَاقَ، عَنْ عَلْقَمَةَ، عَنْ عَبْدِ اللَّهِ، قَالَ لَقَدْ رَأَيْنَا رَسُولَ اللَّهِ ـ صلى الله عليه وسلم ـ يُصَلِّي فِي النَّعْلَيْنِ وَالْخُفَّيْنِ .
also referenced under: Book 5, Hadith 1092 (In-Book) & Volume 2, Book 5, Hadith 1039 (DarusSalam)