question #1 Sahih Muslim 528a, Book 5, Hadith 21 : What is the Islamic perspective on building places of worship over graves?

Umm Habiba and Umm Salama made a mention before the Messenger of Allah (ﷺ) of a church which they had seen in Abyssinia and which had pictures in it. The Messenger of Allah (ﷺ) said: When a pious person amongst them (among the religious groups) dies they build a place of worship on his grave, and then decorate it with such pictures. They would be the worst of creatures on the Day of judgment in the sight of Allah.