عَنْ عَلِيٍّ رَضِيَ اللَّهُ عَنْهُ قَالَ: كَانَ رَسُولُ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَآلِهِ وَسَلَّمَ يُوْتِرُ فِي أَوَّلِ اللَّيْلِ وَفِي وَسَطِهِ وَفِي آخِرِهِ، ثُمَّ ثَبَتَ لَهُ الْوِتْرُ فِي آخِرِهِ
Sayyiduna Ali (may Allah be pleased with him) says: The Messenger of Allah (peace and blessings be upon him) would sometimes perform Witr in the early part of the night, sometimes in the middle part, and at times in the last part of the night. Later on, the Witr of the Messenger of Allah (peace and blessings be upon him) would be in the last part of the night only.