Abu Dawud Book 2, Hadith Number 854.Abu Dawud Book 2. Prayer Chapter : Not known. Narated By AbuMas’ud al-Badri : The Prophet (PBUH) said: A man’s prayer does not avail him unless he keeps his back steady when bowing and prostrating. Related Previous Post Abu Dawud Book 2, Hadith Number 856. Next Post Abu Dawud Book 2, Hadith Number 850.