Based on my little knowledge: These are are Jins and they bring information to the person in whose control or company they are. They visit as per the instructions of their controller and they collect information as instructed. They can provide all the information which is spoken but I think they can't tell him those things which are yet not spoken in words and are still in the minds of targeted persons.


Source: It is known from the persons who claim that we have muwakils in our control.

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"Tumhary nafs ki qeemat Janat hay isy Janat say kam qeemat pey na bechna."
"Jiyo to istarh ky log tum sy milny ko tarsy; maro to istrah k log tumharee mot par royain"