Sahih Al Bukhari Hadith Number 792

Narrated Al-Bara: The bowing, the prostration the sitting in between the two prostrations and the standing after the bowing of the Prophet (peace be upon him) but not qiyam (standing in the prayer) and qu`ud (sitting in the prayer) used to be approximately equal (in duration).

10  Call to Prayers (Adhaan)
Hadith number 792
Volume no 1
Chapter: 121 (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.)