Sunan Abi Dawud, Hadith 843 ⓘ
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.
حَدَّثَنَا 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 .
also referenced under: Hadith 844 (DarusSalam) & Book 3, Hadith 843 (USC-MSA)