Muwatta Malik, Book 8, Hadith 323 (In-Book)

Yahya related to me from Malik from Rabia ibn Abi Abd ar-Rahman that Muhammad ibn Amr ibn Hazm used to pray in a single long shirt.

وَحَدَّثَنِي عَنْ مَالِكٍ، عَنْ رَبِيعَةَ بْنِ أَبِي عَبْدِ الرَّحْمَنِ، أَنَّ مُحَمَّدَ بْنَ عَمْرِو بْنِ حَزْمٍ، كَانَ يُصَلِّي فِي الْقَمِيصِ الْوَاحِدِ ‏.‏

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also referenced under: Book 8, Hadith 34 (USC-MSA)