صَحِيحُ مُسْلِمٍ
Sahih Muslim 971 a
The Book of Prayer - Funerals
Prohibition against sitting and praying on graves
وَحَدَّثَنِي زُهَيْرُ بْنُ حَرْبٍ، حَدَّثَنَا جَرِيرٌ، عَنْ سُهَيْلٍ، عَنْ أَبِيهِ، عَنْ أَبِي هُرَيْرَةَ، قَالَ قَالَ رَسُولُ اللَّهِ صلى الله عليه وسلم لأَنْ يَجْلِسَ أَحَدُكُمْ عَلَى جَمْرَةٍ فَتُحْرِقَ ثِيَابَهُ فَتَخْلُصَ إِلَى جِلْدِهِ خَيْرٌ لَهُ مِنْ أَنْ يَجْلِسَ عَلَى قَبْرٍ .
Abu Huraira reported Allah's Messenger (ﷺ) as saying: It is better that one of you should sit on live coals which would burn his clothing and come in contact with his skin than that he should sit on a grave.
Sahih Muslim, 971 aSahihصحيح