Bulugh al-Maram
Jabir (RAA) narrated that the Messenger of Allah (ﷺ) prohibited whitening a grave with plaster, to sit on it or to build over it (such as a dome).’ Related by Muslim.
وَلِمُسْلِمٍ عَنْهُ: { نَهَى رَسُولُ اَللَّهِ - صلى الله عليه وسلم -أَنْ يُجَصَّصَ الْقَبْرُ, وَأَنْ يُقْعَدَ عَلَيْهِ, وَأَنْ يُبْنَى عَلَيْهِ } 1 .
Reference