Sahih Al Bukhari Hadith Number 1079

Narrated Ibn `Umar.: Whenever the Prophet (peace be upon him) recited the Sura which contained the prostration of recitation he used to prostrate and then, we, too, would prostrate and some of us did not find a place for prostration.

17  Prostration During Recital of Qur’an
Hadith number 1079
Volume no 2
Chapter: 12 ( Whoever does not find a place for prostration (with the Imam) because of overcrowding)