Call to Prayers (Adhaan)
10/127. Chapter:
To stand Straight with calmness on raising the head from bowing
قَالَ أَبُو حُمَيْدٍ رَفَعَ النَّبِيُّ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ وَاسْتَوَى جَالِسًا حَتَّى يَعُودَ كُلُّ فَقَارٍ مَكَانَهُ.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.
Sahih Bukhari
حَدَّثَنَا أَبُو الْوَلِيدِ، قَالَ حَدَّثَنَا شُعْبَةُ، عَنِ الْحَكَمِ، عَنِ ابْنِ أَبِي لَيْلَى، عَنِ الْبَرَاءِ ـ رضى الله عنه ـ قَالَ كَانَ رُكُوعُ النَّبِيِّ صلى الله عليه وسلم وَسُجُودُهُ وَإِذَا رَفَعَ رَأْسَهُ مِنَ الرُّكُوعِ وَبَيْنَ السَّجْدَتَيْنِ قَرِيبًا مِنَ السَّوَاءِ.
Narrated Al-Bara': The bowing, the prostrations, the period of standing after bowing and the interval between the two prostrations of the Prophet (ﷺ) used to be equal in duration .
Reference : Sahih al-Bukhari 801In-book reference : Book 10, Hadith 196USC-MSA web (English) reference : Vol. 1, Book 12, Hadith 766