Bulugh al-Maram, Book 3, Hadith 40 (In-Book)

Umm ‘Atiyah (RAA) narrated, ‘We were forbidden to accompany funeral processions, but this prohibition was not mandatory for us.’ Agreed upon.

وَعَنْ أُمِّ عَطِيَّةَ رَضِيَ اللَّهُ عَنْهَا قَالَتْ: { نُهِينَا عَنِ اتِّبَاعِ الْجَنَائِزِ, وَلَمْ يُعْزَمْ عَلَيْنَا } مُتَّفَقٌ عَلَيْه ِ 1‏.‏ ‏1 ‏- صحيح.‏ رواه البخاري (1287)‏، ومسلم (938)‏، وانظر "ناسخ الحديث" (314)‏.‏

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also referenced under: Book 3, Hadith 596 (English)