WHEN TO OFFER THE WITR PRAYER H 1156 "The Messenger of Allah, praise and peace be upon him, offered the Witr prayer in either the first part of the night, the middle of it, or at its end in which case he finished his Witr prayer near the time of dawn." R 1156 Bukhari and Muslim with a chain up to Lady Ayesha, wife of the Prophet, may Allah be pleased with her, and Mother of Believers, who related this.
1133- وعن عائشة رضي الله عنها ، قالت : مِنْ كُلِّ اللَّيْلِ قَدْ أَوْتَرَ رسول الله صلى الله عليه وآله وسلم ، مِنْ أَوَّلِ اللَّيْلِ، وَمِنْ أوْسَطِهِ، وَمِنْ آخِرِهِ، وَانْتَهَى وِتْرُهُ إِلَى السَّحَرِ . متفقٌ عَلَيْهِ .