Musnad Abu Ya'la al-Mawsili 160:70

Ishaq ibn Abi Isra'il and a group said: Abd al-Rahman ibn Muhammad narrated to us, from al-Ala', from his father, from Abu Hurayrah, that the Messenger of Allah (may Allah bless him and grant him peace) said: "The world is the prison of the believer and the paradise of the disbeliever."