Musnad Ahmad 30:537

'Abd al-Razzaq narrated to us, Ma'mar narrated to us, from Hammam, from Abu Hurayrah, who said: The Messenger of Allah (peace and blessings of Allah be upon him) said: "How excellent it is for the servant that Allah takes his soul while he is in good worship of his Lord and in obedience to his Master. How excellent it is for him, and how excellent it is for him."