What is the ruling of the Shari'ah concerning a man, 75 years of age, who hates his wife, insults her, accuses her of treachery, and claims to have divorced her privately, and what is the effect of this on his family, especially after their return from Hajj?

Accusing a man's wife of infidelity is serious. If he has no proof, he is a slanderer, and slander is one of the gravest sins. His cursing and reviling her is a serious matter, for cursing a believer is like killing him. His supplicating against her without a just cause is impermissible and an injustice. Heartfelt hatred is not a matter of choice for a person, but it must not lead to injustice. If there is no apparent reason for the hatred, it could be due to the evil eye, jinn possession, or magic, and ruqyah (Islamic exorcism) is recommended. If he uttered a divorce, it takes effect, whether someone heard him or not. However, if he divorced in his mind, then mental discourse is not held accountable.