Muwatta Malik, Book 48, Hadith 19 (USC-MSA)

Yahya related to me from Malik that Ishaq ibn Abdullah ibn Abi Talha said, "Anas ibn Malik said, 'I saw Umar ibn al-Khattab when he was the amir of Madina. Three patches were sewn between his shoulders, one patched over the other.' ''

وَحَدَّثَنِي عَنْ مَالِكٍ، عَنْ إِسْحَاقَ بْنِ عَبْدِ اللَّهِ بْنِ أَبِي طَلْحَةَ، أَنَّهُ قَالَ قَالَ أَنَسُ بْنُ مَالِكٍ رَأَيْتُ عُمَرَ بْنَ الْخَطَّابِ وَهُوَ يَوْمَئِذٍ أَمِيرُ الْمَدِينَةِ وَقَدْ رَقَعَ بَيْنَ كَتِفَيْهِ بِرُقَعٍ ثَلاَثٍ لَبَّدَ بَعْضَهَا فَوْقَ بَعْضٍ ‏.‏

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also referenced under: Book 48, Hadith 1673 (In-Book)