ما هي الصلاة بنية المفارقة؟

It is permissible for the ma'mum (follower) to separate from the imam (leader) in several situations: if the imam prolongs the prayer to an extent that causes undue hardship for the ma'mum, or if an incident occurs to the imam, or if the ma'mum is praying a different prayer from the imam (such as praying Fajr behind someone praying Dhuhr), then he may separate from him upon completing his own prayer.

As for a person praying individually with the imam with the intention of praying alone, whereby he follows him in actions but without the intention of iqtida' (following), some jurists have permitted this, considering that the follower is following him in form but not in reality, and his prayer is valid without the condition of intending to follow. This is resorted to by one who fears harm if he prays alone, while knowing the imam's condition that might invalidate his prayer.