Riyad as-Salihin, Book 18, Hadith 1767 (In-Book) ⓘ
Jabir (May Allah be pleased with him) said: The Messenger of Allah forbade that the graves should be plastered (made into permanent structures), used as sitting places (for the people) or building over them.[Muslim].
عن جابر رضي الله عنه قال: نهى رسول الله صلى الله عليه وسلم أن يجصص القبر، وأن يقعد عليه، وأن يبنى عليه. ((رواه مسلم))