Ali (bin Abu Talib) RA reported: The Witr prayer is not obligatory as the prescribed Salat (prayers), but the Messenger of Allah PBUH observed it as his regular practice (Sunnah). He PBUH said, “Allah is Witr (single, odd) and loves what is Witr. So perform Witr prayer. O followers of Qur’an, observe Witr (prayer).”
(Tirmidhi and Abu Dawud)
