It was narrated that ‘Imran bin Husain and Abu Barzah said: “We went out with the Messenger of Allah (ﷺ) 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 (ﷺ) said: ‘Are you adopting the practice of the days of ignorance?’ or; ‘Are you imitating the behavior 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.”
Source: sunnah.com
Other translations
Arabic
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 .
sunnah.com