Hadith: During my ascent to heaven, I passed by a group of people with copper nails scratching their faces and chests. I asked: O Jibrīl, who are these? He replied: These are the ones who eat the flesh of people (by backbiting) and slander them

عن أنس بن مالك رضي الله عنه مرفوعاً: «لما عُرِجَ بي مَرَرْتُ بقوم لهم أظْفَارٌ من نُحَاسٍ يَخْمِشُونَ وُجُوهَهُمْ وَصُدُورَهُم فقلت: مَنْ هؤُلاءِ يا جِبْرِيل؟ قال: هؤلاء الذين يَأكُلُونَ لحُوم الناس، ويَقَعُون في أعْرَاضِهم!».
[حسن] - [رواه أبو داود وأحمد]

Anas ibn Mālik (may Allah be pleased with him) reported that the Prophet (may Allah's peace and blessings be upon him) said: "During my ascent to heaven, I passed by a group of people with copper nails scratching their faces and chests. I asked: 'O Jibrīl, who are these?' He replied: 'These are the ones who eat the flesh of people (by backbiting) and slander them.'"
[Good hadith] - [Narrated by Abu Daoud - Narrated by Ahmad]

Explanation

Meaning of this Hadīth: When the Prophet (may Allah's peace and blessings be upon him) was taken up to heaven on the Night of Ascension, he came across a group of people who were scratching their bodies with their copper nails. He wondered at their state and asked Jibrīl: "Who are these people, and why are they doing this to themselves?" Jibrīl replied that those were the ones who used to backbite people and slander them.