A'isha reported:The Messenger of Allah (ﷺ) said during his illness from which he never recovered: Allah cursed the Jews and the Christians that they took the graves of their prophets as mosques. She ('A'isha) reported: Had it not been so, his (Prophet's) grave would have been in an open place, but it could not be due to the fear that it may not be taken as a mosque

English translation · Sahih Muslim