From What Kind of Person Should One Seek Treatment
Question
Please tell me some method, in accordance with the religion, by acting upon which I may be freed forever from the illness of doubt, suspicion, and whispering thoughts (waswasa)?
Answer
The reality is that the sick person should not treat himself, but should act upon the opinion of an expert, trustworthy reformer (muslih). You too should choose for yourself a person who is a scholar (‘alim), a follower of the Sunna, who has undergone spiritual purification (tazkiya)
Source: Fatawa Mahmudiyya
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