Sunan Abi Dawud 844
سنن أبي داود#844Sahihحَدَّثَنَا مُسَدَّدٌ، حَدَّثَنَا هُشَيْمٌ، عَنْ خَالِدٍ، عَنْ أَبِي قِلاَبَةَ، عَنْ مَالِكِ بْنِ الْحُوَيْرِثِ، أَنَّهُ رَأَى النَّبِيَّ صلى الله عليه وسلم إِذَا كَانَ فِي وِتْرٍ مِنْ صَلاَتِهِ لَمْ يَنْهَضْ حَتَّى يَسْتَوِيَ قَاعِدًا .
Abu Qilabah said:Malik b. al-Huwairith saw that the prophet (may peace by upon him) would not stand at the end of the first or the third rak’ah until he sat down straight
Scholarly Authentication
The label above is the grade most of these scholars gave — one dissenting opinion no longer speaks for all of them. If any scholar calls a narration fabricated, that verdict is shown instead, whatever the others say. Each scholar's own wording:
Al-AlbaniSahih
Muhammad Muhyi Al-Din Abdul HamidSahih
Shuaib Al ArnautHasan Sahih
Zubair Ali ZaiSahih Bukhari (823)
In-book reference: 2:454