Sunan an-Nasa'i 2344

Abdullah bin 'Amr bin Al-As said:"The Messenger of Allah said: 'The most beloved fasting to Allah, the mighty and sublime, is the fast of Dawud, peace be upon him. He used to fast one day and not the next. And the most beloved prayer to Allah, the mighty and sublime, is the prayer of Dawud, peace be upon him. He used to sleep half the night, stand for one-third of it (in prayer), and sleep for one-sixth of it