The Messenger of Allah ﷺ said, "When one of you is praying, Satan comes to him and tries to distract him the way a man calms his animal. Once he settles him down, he passes wind between his buttocks to divert him from his prayer. So when any of you senses something of that, he should not leave the prayer until he hears a sound or detects an odor that he is certain of."
حدثنا أبو بكر الحنفي حدثنا الضحاك بن عثمان عن سعيد المقبري قال
رسول الله ﷺ إن أحدكم إذا كان في الصلاة جاءه الشيطان فأبس به كما يأبس الرجل بدابته فإذا سكن له أضرط بين أليتيه ليفتنه عن صلاته فإذا وجد أحدكم شيئا من ذلك فلا ينصرف حتى يسمع صوتا أو يجد ريحا لا يشك فيه
Its isnad is sahih. Imam Ahmad narrated the hadith in his Musnad.The meaning of "bas" the camels, or "abassaha," is to drive them, saying to them, "bas, bas."In the hadith, "A people will leave Madinah for Yemen, driving their camels, yet Madinah would be better for them, if only they knew."