What is the religious ruling on someone who uttered a divorce oath to his wife, with whom he had not yet consummated the marriage, and this was unintentional and not in her presence but in front of his mother during a moment of anger?

If you divorce your wife before consummating the marriage, it constitutes a minor, revocable divorce (baynunah sughra). You may remarry her with a new Mahr, a guardian (wali), witnesses, and her consent.

As for conditional divorce, the majority of scholars hold that it takes effect when the condition upon which it is suspended is fulfilled. However, Sheikh Al-Islam Ibn Taymiyyah views it as an oath that necessitates an expiation (kaffarat yamin (definition)) if violated.

Anger does not prevent the occurrence of divorce unless it reaches the point of losing consciousness and awareness. Likewise, uttering a divorce oath in the absence of the wife does not affect its occurrence.

Therefore, if your anger did not reach the point of losing consciousness and you violated your oath, the majority of scholars hold that the divorce takes effect, while Ibn Taymiyyah maintains that an expiation is due. It is preferable to present the matter to a judge to resolve the dispute.

Divorce before consummation or valid seclusion (khalwah shar'iyyah) is considered a minor, revocable divorce. If you did not violate your oath, nothing is incumbent upon you, and it is advisable to be cautious about frequently using divorce pronouncements.