He claims that he circumambulates the Ka’bah in his dreams and tells them about the future
Question

                I got to know a person who told me that in his dreams a Muslim jinn comes to him and he says that he performed tawaaf with him in Makkah and gave him Zamzam water to drink, and he visited the grave of the Prophet (peace and blessings of Allaah be upon him) with him. He says that this all happened on the same night, and until now he says that he performs tawaaf with him in Makkah and visits the grave of the Prophet. This man told me some things about the future and some of them came true. My brother is enchanted by this man and believes everything that he says. I do not have enough knowledge of sharee’ah to be able to prove this man’s claims to be false. How can I get rid of him and convince my brother that this man is a liar?.
Praise be to Allah.
    Firstly: 

    There is nothing wrong or strange about this man saying that 
    he dreamt that a Muslim jinn performed tawaaf with him in Makkah and visited 
    the grave of the Prophet  (peace and blessings of Allaah be upon him). A 
    man may see such things in his dreams, or greater things, such as seeing 
    himself in Paradise or going up into the heaven then coming down, and other 
    things that cannot happen in reality. 

    This applies if he is telling the truth about his dreams, but 
    some charlatans tell lies and deceive people with their false dreams. 

    Secondly: 

    The fact that he speaks about the future indicates that he is 
    one of the fortune-tellers or soothsayers, who deal with the jinn and find 
    out some matters of the unseen from them, as is mentioned in the hadeeth 
    narrated by al-Bukhaari (4701) and Muslim (2228) from Abu Hurayrah (may 
    Allaah be pleased with him), that the Prophet  (peace and blessings of 
    Allaah be upon him) said: “When Allaah decrees a matter in heaven, the 
    angels beat their wings in submission to His words, making a sound like a 
    chain striking a rock. When the fear is banished from their hearts, they 
    say, What is it that your Lord has said? They say: The truth, and He is the 
    Most High, the Most Great. Then the one who is listening out hears that, and 
    those who are listening out are standing one above the other” – Sufyaan [one 
    of the narrators] demonstrated with his hand, holding it vertically with the 
    fingers outspread. – “Perhaps the meteor will hit the listener before he can 
    pass it on to his companion, and burn him, or perhaps it will not hit him 
    until he passes it on to the one who is below him, until they pass it down 
    to earth – or perhaps Sufyaan said: until it reaches the earth – and is put 
    in the mouth of the witch and he tells one hundred lies along with it. So he 
    is believed and they say: Did he not tell us that on such and such a day, 
    such and such would happen, and it came to pass? That is the word that was 
    heard from heaven. So they believe him because of one thing which was heard 
    from heaven.”  

    And al-Bukhaari (7561) and Muslim (2228) narrated that 
    ‘Aa’ishah (may Allaah be pleased with her) said: Some people asked the 
    Prophet  (peace and blessings of Allaah be upon him) about soothsayers. 
    He said: “They are nothing.” They said: O Messenger of Allaah, sometimes 
    they tell us something that turns out to be true. The Messenger of Allaah 
     (peace and blessings of Allaah be upon him) said: “That is a word from 
    the jinn that the jinni snatches, and he cackles it into the ear of his 
    familiar as a hen cackles, but they mix more than a hundred lies with it.” 

    If this man claims to have knowledge of the unseen then he is 
    a kaafir, so beware of going to him, because going to such people and 
    believing them is haraam, because the Prophet  (peace and blessings of 
    Allaah be upon him) said: “Whoever goes to a fortune-teller and asks him 
    about something, his prayer will not be accepted for forty nights.” Narrated 
    by Muslim (2230). 

    This applies if he goes to him and asks him something and 
    does not believe him. But if he believes him, then the Prophet  (peace 
    and blessings of Allaah be upon him) said: “Whoever goes to a soothsayer or 
    fortune-teller and believes what he says, has disbelieved in what was 
    revealed to Muhammad  (peace and blessings of Allaah be upon him).” 
    Narrated by Ahmad (9532) and al-Haakim (15); classed as saheeh by al-Albaani 
    in Saheeh al-Jaami’. 

    Thus it is clear that it is haraam to go to fortune-tellers 
    and believe what they say. 

    Advise your brother and explain that to him, and warn him 
    against keeping company with this man or believing him. 

    We ask Allaah to protect us and you from all evils and 
    temptations. 

    And Allaah knows best.