"The Messenger of Allah forbade building over graves, making them larger or plastering over them." (One of two narrators) Sulaiman bin Musa added: "Or writing on them." (Using translation from Nasāʾī 2027)
«نَهَى رَسُولُ اللَّهِ ﷺ أَنْ يُبْنَى عَلَى الْقَبْرِ أَوْ يُجَصَّصَ أَوْ يَقْعُدَ عَلَيْهِ وَنَهَى أَنْ يُكْتَبَ عَلَيْهِ»