Lady Aisha and Sayyiduna Abdullah bin Abbas (may Allah be pleased with them) narrated that during the illness of his death, the Prophet Muhammad (peace be upon him) would repeatedly place his cloak over his face, and when he felt some relief, he would remove the cloak. In this state of distress and anxiety, the Prophet (peace be upon him) said, "May Allah's curse be upon the Jews and Christians, for they took the graves of their prophets as places of worship." By saying this, he was warning the Ummah against such actions.