Musannaf Ibn Abi Shayba 3:5170

Hashim ibn al-Qasim narrated to us, [saying] Shu'ban narrated to us, from Hilal ibn Abi Humayd al-Ansari, from 'Urwah ibn al-Zubayr, from 'Aishah, who said: The Messenger of Allah (may Allah bless him and grant him peace) said during his illness from which he did not recover: "May Allah curse the Jews and the Christians; they took the graves of their prophets as places of worship." And were it not for that, his grave would have been made prominent, except that he feared it would be taken as a place of worship.