Musnad Ahmad 1153:1111

Muhammad ibn Ja'far narrated to us, Sa'id and Muhammad ibn Bakr narrated to us, Sa'id informed us, from Qatadah, from Sa'id ibn al-Musayyib, from 'Aishah: "That the Messenger of Allah (may Allah bless him and grant him peace) cursed a people who took the graves of their prophets as places of worship." And Muhammad ibn Bakr said: "That the Messenger of Allah (may Allah bless him and grant him peace) cursed peoples." And al-Khaffaf said: "That the Prophet (may Allah bless him and grant him peace) said: 'May Allah curse a people who took...'"