Bulugh al-Maram, Book 16, Hadith 1450 (In-Book)

Abu Hurairah (RAA) narrated that the Messenger of Allah said: “None of you should walk with one shoe, but should either wear them both or take them both off” Agreed upon.

وَعَنْهُ قَالَ: قَالَ رَسُولُ اَللَّهِ ‏- صلى الله عليه وسلم ‏-{ لَا يَمْشِ أَحَدُكُمْ فِي نَعْلٍ وَاحِدَةٍ, وَلْيُنْعِلْهُمَا جَمِيعًا, أَوْ لِيَخْلَعْهُمَا جَمِيعًا } مُتَّفَقٌ عَلَيْهِمَا.‏ (1909)‏.‏ ‏1 ‏- صحيح.‏ رواه البخاري (5855)‏، ومسلم (2097)‏ (68)‏.‏

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also referenced under: Book 16, Hadith 1493 (English)