Mishkat al-Masabih
Mishkat al-Masabih 1225
وَعَنْ عَبْدِ اللَّهِ بْنِ عَمْرٍو قَالَ: قَالَ رَسُولُ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ: «أَحَبُّ الصَّلَاةِ إِلَى اللَّهِ صَلَاةُ دَاوُدَ وَأَحَبُّ الصِّيَامِ إِلَى اللَّهِ صِيَامُ دَاوُدَ كَانَ يَنَامُ نِصْفَ اللَّيْلِ وَيَقُومُ ثُلُثَهُ وَيَنَامُ سُدُسَهُ وَيَصُومُ يَوْمًا وَيُفْطِرُ يَوْمًا»
Unreviewed translation. All hadiths in this collection are available in five languages. Titles and introductions may remain in Arabic.
Abdullah ibn Amr reported that the Messenger of God, peace and blessings be upon him, said: The prayer most beloved to God is the prayer of David, and the fast most beloved to God is the fast of David. He would sleep for half the night, pray for a third of it, and sleep for a sixth of it. He would fast one day and not fast the next.