Narrated Abu Huraira: My friend (the Prophet) advised me to do three things and I shall not leave them till I die, these are: To fast three days every month, to offer the Duha prayer, and to offer witr before sleeping.
Hadith ReferenceSahih Bukhari / The Book of Salat-Ut-Tahajjud (Night Prayer) / Hadith: 1178
Hadith Gradingمحدثین:أحاديث صحيح البخاريّ كلّها صحيحة