All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad is His slave and Messenger.
The soul does not part from the body except by the command from Allaah The Almighty, its Creator and the only One who knows its true nature. He Says (what means): {And they ask you, [O Muhammad], about the soul. Say, "The soul is of the affair of my Lord. And mankind have not been given of knowledge except a little."} [Quran 17:85] The soul only parts from the body in two cases that are clarified in the Quran. The first case is when one sleeps and the second is when one dies. Allaah The Almighty Says (what means):
• {Allaah takes the souls at the time of their death, and those that do not die [He takes] during their sleep. Then He keeps those for which He has decreed death and releases the others for a specified term. Indeed in that are signs for a people who give thought.} [Quran 39:42]
• {And it is He who takes your souls by night and knows what you have committed by day.} [Quran 6:60]
Ibn Qayyim Al-Jawziyyah mentioned that the souls of the believers part from their bodies during their sleep and meet with the souls of the dead. This is proved by the fact that the living may see the dead in a vision and ask them about things. In turn, the dead may inform them of things that they do not know about.
In the interpretation of the previously mentioned verse [39:42], it was reported that Ibn ‘Abbaas learnt that the souls of both the living and the dead meet during sleep and talk together. Then, Allaah The Almighty holds back the souls of the dead and restores those of the living. As-Suddi mentioned the same thing but added that the soul of the dead feels the desire to return to its body but it is held back.
This is the way the souls act by a command from Allaah The Lord of the worlds. What your friend does has nothing to do with the souls because it is only Allaah The Almighty who can summon them or send them back. Actually, it seems that your friend is only summoning the Jinns and making use of them. This is an unlawful act and its doer is severely censured and promised Hell in the Quran. Allaah The Almighty Says in the verse (what means): {And their allies among mankind will say, "Our Lord, some of us made use of others, and we have [now] reached our term, which you appointed for us." He will say, "The Fire is your residence, wherein you will abide eternally, except for what Allaah wills. Indeed, your Lord is Wise and Knowing."} [Quran 6:128] Scholars of Tafseer (Quranic exegesis) said that the relationship mentioned in the verse, ‘making use of each other’, refers to men obeying Jinns in what they order them to do and to Jinns helping men and providing them with the information they ask for about the past and the future. However, the Jinns are indeed liars in most of what they tell man. Allaah The Almighty Says (what means):
• {Shall I inform you upon whom the devils descend? They descend upon every sinful liar. They pass on what is heard, and most of them are liars.} [Quran 26:221-223]
• {And there were men from mankind who sought refuge in men from the jinn, so they [only] increased them in burden.} [Quran 72:6]
It is not true that this person can treat anyone, even if he is far away because Ruqyah must be made directly onto the sick person. This can be done by reciting or by drinking water upon which Quranic verses have been recited or by rubbing oils onto the affected place. Nobody can treat from afar except magicians who utilize the Jinn in the way we have mentioned.
Allaah Knows best.