Musnad Ahmad 1153:500

Hashim narrated to us, Abu Mu'awiyah—meaning Shayban—narrated to us, from Hilal ibn Abi Humayd al-Ansari, from Urwah ibn al-Zubayr, from Aisha, who said: The Messenger of Allah (peace and blessings of Allah be upon him) said during his illness from which he did not recover: "May Allah curse the Jews and the Christians, for they took the graves of their prophets as places of worship." She said: "And were it not for that, his grave would have been made prominent, but he feared that it would be taken as a place of worship."