Prayer (Kitab Al-Salat): Details of Commencing Prayer

Dawud :: Book 3 : Hadith 1034

Narrated Imran ibn Husayn:

The Prophet (peace_be_upon_him) led them in prayer and forgot something, so he made prostrations and uttered the tashahhud, then gave the salutation.

Source materials are from the University of Southern California MSA site
Hadith eBooks converted from Imaan Star