Is turning aside during prayer without necessity disliked?
Chapter on what invalidates the prayer if omitted intentionally or forgetfully
Al-Mughni
Book of Prayer
Primary text
Turning aside during prayer without necessity is disliked. Aisha, may Allah be pleased with her, narrated that the Prophet, peace be upon him, said this turning is a snatching by the devil from the servant's prayer, as recorded by Sa'id ibn Mansur. Furthermore, Abu Dharr reported that Allah remains attentive to the servant during prayer only as long as he does not turn aside, upon which Allah turns away from him. Both narrations are found in Sunan Abi Dawud.
Supporting text
If turning aside occurs due to a need, it is not disliked. Evidence for this is found in the narration where the Prophet, peace be upon him, prayed while looking toward a valley where he had sent a guard (narrated by Abu Dawud). Also, Ibn Abbas narrated that the Messenger of Allah, peace be upon him, would turn right and left but not twist his neck completely behind his back (narrated by An-Nasa'i).