Sunan an-Nasa'i 1630
سنن النسائي#1630SahihIt was narrated from 'Amr bin Aws that he heard Abdullah bin Amr bin Al-'As say:"The Messenger of Allah (ﷺ) said: 'The most beloved of fasting to Allah is the fasting of Dawud, peace be upon him. He used to fast one day and not the next. And the most beloved of prayer to Allah (SWT) is the prayer of Dawud. He used to sleep half the night, spend one-third of the night in prayer and sleep for one-sixth of it
Scholarly Authentication
We show the most cautious grade (weakest-wins) as the overall label. Individual scholars graded it as follows:
Abu GhuddahSahih
Al-AlbaniSahih
Zubair Ali ZaiSahih - Agreed Upon
In-book reference: 20:33