Sahih Al Bukhari Hadith Number 801

Narrated Al-Bara’: The bowing, the prostrations, the period of standing after bowing and the interval between the two prostrations of the Prophet (peace be upon him) used to be equal in duration .

10  Call to Prayers (Adhaan)
Hadith number 801
Volume no 1
Chapter: 127 (To stand Straight with calmness on raising the head from bowing)