Hadith 195

Sahih Bukhari

Book 10: Call to Prayers (Adhaan)

Chapter 127

To stand Straight with calmness on raising the head from bowing

باب الاِطْمَأْنِينَةِ حِينَ يَرْفَعُ رَأْسَهُ مِنَ الرُّكُوعِ

And Abu Humaid said: The Prophet ﷺ rose (from bowing) and stood straight till all the vertebra of his spinal column came to a natural position. ​​
قَالَ أَبُو حُمَيْدٍ رَفَعَ النَّبِيُّ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ وَاسْتَوَى جَالِسًا حَتَّى يَعُودَ كُلُّ فَقَارٍ مَكَانَهُ.
Sahih al-Bukhari 800
حَدَّثَنَا أَبُو الْوَلِيدِ، قَالَ حَدَّثَنَا شُعْبَةُ، عَنْ ثَابِتٍ، قَالَ كَانَ أَنَسٌ يَنْعَتُ لَنَا صَلاَةَ النَّبِيِّ صلى الله عليه وسلم فَكَانَ يُصَلِّي وَإِذَا رَفَعَ رَأْسَهُ مِنَ الرُّكُوعِ قَامَ حَتَّى نَقُولَ قَدْ نَسِيَ‏.‏
Thabit:

Anas used to demonstrate to us the prayer of the Prophet (ﷺ) and while demonstrating, he used to raise his head from bowing and stand so long that we would say that he had forgotten (the prostration).