(33) باب النَّهْىِ عَنِ الْجُلُوسِ، عَلَى الْقَبْرِ وَالصَّلاَةِ عَلَيْهِ
Abu Marthad al-Ghanawi reported Allah's Messenger (ﷺ) as saying:
Do not pray facing towards the graves, and do not sit on them. (ID)
Reference (ID): Sahih Muslim 972 b (ID)
In-book reference (ID): Book 11, Hadith 127 (ID)
USC-MSA web (English) reference(deprecated numbering scheme): Book 4, Hadith 2122 (ID)