عَنْ عَلِيٍّ رَضِيَ اللَّهُ عَنْهُ قَالَ: الْوِتْرُ لَيْسَ بِحَتْمٍ كَالصَّلَاةِ وَلَكِنَّهُ سُنَّةٌ سَنَّهَا رَسُولُ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَآلِهِ وَسَلَّمَ
Sayyiduna Ali (may Allah be pleased with him) says: The Witr prayer is not as obligatory as the obligatory prayers; rather, it is a Sunnah, which the Messenger of Allah (peace and blessings be upon him) has declared to be Sunnah.