Sunan an-Nasa'i 760
سنن النسائي#760SahihIt 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
Scholarly Authentication
We show the most cautious grade (weakest-wins) as the overall label. Individual scholars graded it as follows:
Abu GhuddahSahih
Al-AlbaniSahih
Zubair Ali ZaiSahih Muslim
In-book reference: 9:19