Does divorce occur if the wife goes to the husband's family home after the husband says: "By Haram, you will not go to my family's house," knowing that he did not intend divorce?

If you swore an oath of tahrim (prohibition) upon your wife that she should not go to her parents' house, then if she does not go, nothing is incumbent upon you. However, if she does go, the oath has been broken, and the ruling on breaking the oath depends on your intention:

1. If you intended ẓihār (likening one's wife to an unmarriageable kin): The expiation for ẓihār becomes binding upon you.

2. If you intended divorce: A divorce occurs.

3. If you intended an oath by Allah or had no specific intention: The expiation for an oath becomes binding upon you.

The evidence for this is Allah's Almighty saying: "O Prophet, why do you prohibit that which Allah has made lawful for you, seeking to please your wives? And Allah is Forgiving and Merciful. Allah has already ordained for you [Muslims] the dissolution of your oaths. And Allah is your protector, and He is the Knowing, the Wise." (At-Tahrim: 1-2).