Hadith on Graves: Strong warning not to sit on graves

Abu Huraira reported: The Messenger of Allah, peace and blessings be upon him, said, “For one of you to sit upon a hot coal and burn himself and his clothes would be better than sitting upon a grave.”

Source: Ṣaḥīḥ Muslim 971

Grade: Sahih (authentic) according to Muslim

عَنْ أَبِي هُرَيْرَةَ قَالَ قَالَ رَسُولُ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ لَأَنْ يَجْلِسَ أَحَدُكُمْ عَلَى جَمْرَةٍ فَتُحْرِقَ ثِيَابَهُ فَتَخْلُصَ إِلَى جِلْدِهِ خَيْرٌ لَهُ مِنْ أَنْ يَجْلِسَ عَلَى قَبْرٍ

971 صحيح مسلم كتاب الجنائز باب النهي عن الجلوس على القبر والصلاة عليه