‘Abdallah b. ‘Amr reported God’s Messenger as saying, “The prayer dearest to God is David’s and the fasting dearest to God is David’s. He would sleep half the night, get up to pray for a third of it, then sleep the remaining sixth; and he would fast on alternate days." (Bukhari and Muslim.)
Hadith Referenceمشكوة المصابيح / كتاب الصلاة / 1225
Hadith Gradingالألبانی:مُتَّفَقٌ عَلَيْهِ | زبیر علی زئی:متفق عليه
Hadith Takhrij´تحقيق و تخريج: محدث العصر حافظ زبير على زئي رحمه الله` «متفق عليه، رواه البخاري (1131) و مسلم (189/ 1159)»