What is tribulation, and is a man's knowledge of his wife's or one of his friends' betrayal of him considered a tribulation?

If a man discovers the betrayal of his wife or friend, this is a trial that necessitates patience to elevate ranks and expiate sins. The husband must not tolerate impurity among his family and should work to protect his wife and prevent her from falling into betrayal by obliging her to observe modesty and prohibiting her from mingling with non-mahram men; otherwise, he would be a dayyuth [a pimp or a cuckold, one who has no jealousy regarding his womenfolk]. He must also advise his friend and remind him of Allah if he confirms his betrayal, and take necessary precautions to prevent the recurrence of betrayal, especially if it relates to honor. Lenience in allowing friends to enter upon women leads to immorality and violation of honor.