Sunan an-Nasa'i, Hadith 1153 ⓘ
It was narrated that Abu Qibalah said: "Malik bin Al-Huwairith used to come to us and say: "Shall I not tell you about the prayer of the Messenger of Allah?" He was praying at a time other than the time of prayer, and when he raised his head from the second prostration in the first rak'ah, he settled in a seated position, then he stood up, and he supported himself on the ground (while doing so)."
أَخْبَرَنَا مُحَمَّدُ بْنُ بَشَّارٍ، قَالَ حَدَّثَنَا عَبْدُ الْوَهَّابِ، قَالَ حَدَّثَنَا خَالِدٌ، عَنْ أَبِي قِلاَبَةَ، قَالَ كَانَ مَالِكُ بْنُ الْحُوَيْرِثِ يَأْتِينَا فَيَقُولُ أَلاَ أُحَدِّثُكُمْ عَنْ صَلاَةِ، رَسُولِ اللَّهِ صلى الله عليه وسلم فَيُصَلِّي فِي غَيْرِ وَقْتِ الصَّلاَةِ فَإِذَا رَفَعَ رَأْسَهُ مِنَ السَّجْدَةِ الثَّانِيَةِ فِي أَوَّلِ الرَّكْعَةِ اسْتَوَى قَاعِدًا ثُمَّ قَامَ فَاعْتَمَدَ عَلَى الأَرْضِ .
also referenced under: Book 12, Hadith 125 (In-Book) & Volume 2, Book 12, Hadith 1154 (DarusSalam)