حَدَّثَنَا عَفَّانُ حَدَّثَنَا شُعْبَةُ قَالَ أَبُو إِسْحَاقَ أَنْبَأَنِي غَيْرَ مَرَّةٍ قَالَ سَمِعْتُ عَاصِمَ بْنَ ضَمْرَةَ عَنْ عَلِيٍّ رَضِيَ اللَّهُ عَنْهُ أَنَّهُ قَالَ مِنْ كُلِّ اللَّيْلِ قَدْ أَوْتَرَ رَسُولُ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ مِنْ أَوَّلِهِ وَأَوْسَطِهِ وَآخِرِهِ وَانْتَهَى وِتْرُهُ إِلَى آخِرِ اللَّيْلِ
مسند امام احمد بن حنبل · Hadith 825
It was narrated from 'Ali (RA) that he said: The Messenger of Allah (PBUH) prayed Witr at all times of the night, at the beginning, in the middle and at the end, and finally he prayed Witr at the end of the night.
Translated by Dr. Muhammad Muhsin Khan · Reviewed by Islamic University of Madinah · Published March 2020