What is the method for treating a father who suffers from excessive suspicion towards those closest to him, a condition that has appeared in the last two months and is causing great suffering to his wife?

The successful treatment for the problem of a father's jealousy is for the mother to stay away from anything that arouses her husband's suspicion, and not to allow her husband's brother or anyone else to enter upon her in his absence, and to keep away from situations of doubt, in compliance with the Prophet's (peace and blessings be upon him) saying: "Beware of entering upon women." It was said: "O Messenger of Allah, what about the in-law?" He said: "The in-law is death." And the father should control his jealousy and not have ill thoughts about his wife if there is no doubt, due to his (peace and blessings be upon him) saying: "Indeed, some jealousy is loved by Allah Almighty, and some is hated by Allah. As for the jealousy that Allah loves, it is jealousy regarding suspicion. And the jealousy that Allah hates is jealousy in the absence of suspicion," and his saying: "Beware of suspicion, for suspicion is the falsest of speech."