What is the legal ruling for someone who swore by triple divorce upon his wife if she intervened while he was disciplining his son, with the intention of threatening, not divorcing? And does the divorce occur if the wife does intervene?

You swore by triple divorce that if your wife intervened while you were disciplining your son, she would no longer be your wife. You state that you did not intend divorce but rather a threat, and you did not clarify your intention with the phrase "she would no longer be your wife." The ruling on your oath depends on knowing your intention. If your intention was fulfilled by her no longer being your wife upon her intervention, then your oath is fulfilled, and no divorce occurs. If it was not fulfilled, then you have broken your oath, and your oath entails triple divorce. The prevalent fatwa is that triple divorce occurs, leading to an irrevocable divorce (baynunah kubra). Some scholars are of the opinion that divorce does not occur in cases of threat, and instead, expiation for a broken oath (kaffarat yamin) becomes obligatory. We advise presenting the matter to trustworthy scholars.