An excerpt from the book entitled “Purification of the Heart – Signs, Symptoms, and Cures of the Spiritual Diseases of the Heart.” By Hamza Yusuf.
“Poem Verses 121-24
Some assumptions are not permissible, such as holding a bad opinion about someone who manifests righteous behavior.
This means that your heart is convinced and you have judged him based on your heart’s suspicions without proof that warrants such an assumption.
There is nothing wrong with having doubts about someone or having a bad opinion of him if it based on sound reasoning and is not arbitrary.
Thus our bad opinion of some profligate whose actions indicate his (corruption) is not prohibited.”
“Scholars have been advised that one should have even beware of forming conclusions based on the bad appearances of people, for it could be that God veils their goodness from others.
“But having a bad opinion of someone without a cause is considered a malady of the heart: “O you who believe, avoid suspicion, for some suspicion is sinful (Quran, 49:12). The Prophet s.a.w. said, “Beware of a bad opinion because it is the most false of speech.” If someone says to you that a given person is bad, ask for proof. Without proof it is tantamount to a lie. Shari’a is based on proof and not conjecture.
“Having doubts about people is different from decidedly judging them negatively. Concluding a bad opinion in the presence of ample evidence is common sense. But when people repent, they should not have their past held against them. There is a hadith that says, “There are two things that no believer has been given anything better: a good opinion of God and a good opinion of the servants of God.”
“Even if something unpleasant occurs, there is good in it.”