Sunan Ibn Majah, Volume 2, Book 6, Hadith 1485 (DarusSalam) ⓘ

It was narrated that ‘Imran bin Husain and Abu Barzah said: “We went out with the Messenger of Allah to attend a funeral, and he saw some people who had cast aside their upper sheets and were walking in their shirts only. The Messenger of Allah said: ‘Are you adopting the practice of the days of ignorance?’ or; ‘Are you imitating the behaviour of the days of ignorance? I was about to supplicate against you that you would return in a different form.’ So they put their sheets back on and never did that again.”

حَدَّثَنَا أَحْمَدُ بْنُ عَبْدَةَ، أَخْبَرَنِي عَمْرُو بْنُ النُّعْمَانِ، حَدَّثَنَا عَلِيُّ بْنُ الْحَزَوَّرِ، عَنْ نُفَيْعٍ، عَنْ عِمْرَانَ بْنِ الْحُصَيْنِ، وَأَبِي، بَرْزَةَ قَالاَ خَرَجْنَا مَعَ رَسُولِ اللَّهِ ـ صلى الله عليه وسلم ـ فِي جِنَازَةٍ فَرَأَى قَوْمًا قَدْ طَرَحُوا أَرْدِيَتَهُمْ يَمْشُونَ فِي قُمُصٍ فَقَالَ رَسُولُ اللَّهِ ـ صلى الله عليه وسلم ـ ‏ "‏ أَبِفِعْلِ الْجَاهِلِيَّةِ تَأْخُذُونَ - أَوْ بِصُنْعِ الْجَاهِلِيَّةِ تَشَبَّهُونَ - لَقَدْ هَمَمْتُ أَنْ أَدْعُوَ عَلَيْكُمْ دَعْوَةً تَرْجِعُونَ فِي غَيْرِ صُوَرِكُمْ ‏" ‏ ‏.‏ قَالَ فَأَخَذُوا أَرْدِيَتَهُمْ وَلَمْ يَعُودُوا لِذَلِكَ ‏.‏