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

Dawud :: Book 3 : Hadith 1001

Narrated AbuHurayrah:

The Prophet (peace_be_upon_him) said: Cannot any one of you (according to the version of the narrator AbdulWarith) step forward or backward or at his right or left. The version of Hammad added: during prayer; that is, in supererogatory prayer.