What is the ruling of Islamic law regarding the marriage of a man to a woman, when he discovered after the marriage that she possessed an ID card belonging to a young man, and after he forgave her, he traveled again, then upon his return from his journey, he noticed his wife's inclination towards his brother, whom she had not even seen?

It is advisable to moderate jealousy and be balanced, for our religion calls for strengthening the family. One should act upon the hadith (definition): "A believing man should not hate a believing woman; if he dislikes one of her characteristics, he will be pleased with another." And the hadith prohibiting a man from suddenly returning to his family at night to spy on them. Seek excuses for your wife and have a good opinion of her. These obsessions are from Satan, so seek refuge in Allah from him. Bring your wife to live with you and treat her well, and follow the Prophet's (peace and blessings be upon him) advice: "The most complete in faith among believers are those with the best character, and the best of you are those who are best to their women." As for slapping one's wife on the face, it is forbidden by Sharia (definition). Beating is not permissible except in cases of nushuz (disobedience) and with conditions, and it is better to avoid it.