(11) باب النَّهْىِ عَنِ الصَّلاَةِ، إِلَى الْقَبْرِ
It was narrated that Abu Marthad al Ghanawi said:
"The Messenger of Allah(ﷺ)said: 'Do not pray toward graves and do not sit on them.'"
Reference: Sunan an-Nasa'i 760
In-book reference: Book 9, Hadith 19
English translation: Vol. 1, Book 9, Hadith 761