And what is said regarding the limit of the completion of bowing and of keeping the back straight and the calmness with which it is performed.

Sahih al-Bukhari · Book 10 · Hadith 792

حَدَّثَنَا بَدَلُ بْنُ الْمُحَبَّرِ، قَالَ حَدَّثَنَا شُعْبَةُ، قَالَ أَخْبَرَنِي الْحَكَمُ، عَنِ ابْنِ أَبِي لَيْلَى، عَنِ الْبَرَاءِ، قَالَ كَانَ رُكُوعُ النَّبِيِّ صلى الله عليه وسلم وَسُجُودُهُ وَبَيْنَ السَّجْدَتَيْنِ وَإِذَا رَفَعَ مِنَ الرُّكُوعِ، مَا خَلاَ الْقِيَامَ وَالْقُعُودَ، قَرِيبًا مِنَ السَّوَاءِ‏.‏

Narrated Al-Bara: The bowing, the prostration the sitting in between the two prostrations and the standing after the bowing of the Prophet (ﷺ) but not qiyam (standing in the prayer) and qu`ud (sitting in the prayer) use…