Sunan an-Nasa'i, Book 12, Hadith 124 (In-Book) ⓘ
It was narrated that Malik bin Al-Huwairith said: "I saw the Messenger of Allah pray, and when he was in an odd-numbered rak'ah, he did not get up until he had settled in a sitting position."
أَخْبَرَنَا عَلِيُّ بْنُ حُجْرٍ، قَالَ أَنْبَأَنَا هُشَيْمٌ، عَنْ خَالِدٍ، عَنْ أَبِي قِلاَبَةَ، عَنْ مَالِكِ بْنِ الْحُوَيْرِثِ، قَالَ رَأَيْتُ رَسُولَ اللَّهِ صلى الله عليه وسلم يُصَلِّي فَإِذَا كَانَ فِي وَتْرٍ مِنْ صَلاَتِهِ لَمْ يَنْهَضْ حَتَّى يَسْتَوِيَ جَالِسًا .
also referenced under: Hadith 1152 (Reference) & Volume 2, Book 12, Hadith 1153 (DarusSalam)