Hadith 1200

(حديث مرفوع) حَدَّثَنَا عَبْدُ الرَّزَّاقِ ، أَخْبَرَنَا سُفْيَانُ ، عَنْ لَيْثٍ ، عَنْ مُجَاهِدٍ ، عَنْ أَبِي مَعْمَرٍ ، قَالَ : كُنَّا مَعَ عَلِيٍّ رَضِيَ اللَّهُ عَنْهُ ، " فَمَرَّ بِهِ جَنَازَةٌ ، فَقَامَ لَهَا نَاسٌ ، فَقَالَ عَلِيٌّ رَضِيَ اللَّهُ عَنْهُ : مَنْ أَفْتَاكُمْ هَذَا ؟ ! فَقَالُوا : أَبُو مُوسَى ، قَالَ : إِنَّمَا فَعَلَ ذَلِكَ رَسُولُ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ مَرَّةً ، وَكَانَ يَتَشَبَّهُ بِأَهْلِ الْكِتَابِ ، فَلَمَّا نُهِيَ انْتَهَى " .
Abu Ma'mar says that once we were present with Sayyiduna Ali (may Allah be pleased with him), a funeral passed by there, and people stood up upon seeing it. Sayyiduna Ali (may Allah be pleased with him) asked, "Who told you about this ruling?" The people mentioned the name of Sayyiduna Abu Musa Ash'ari (may Allah be pleased with him). Sayyiduna Ali (may Allah be pleased with him) said that the Prophet (peace and blessings be upon him) did this only once, and that too because the Prophet (peace and blessings be upon him) used to adopt the practices of the People of the Book, but when it was prohibited, he (peace and blessings be upon him) stopped.
Hadith Reference مسند احمد / مسند الخلفاء الراشدين / 1200
Hadith Grading حکم دارالسلام: صحيح، ليث ضعيف وقد توبع