Is it possible to retract an oath of conditional divorce, uttered in a state of anger, or is expiation obligatory to avoid the divorce taking effect?

If you make your wife's divorce conditional upon something, the fatwa (religious ruling) that we adhere to is that you cannot retract it. If the condition is met, the divorce takes place, whether you intended to effect the divorce or merely to threaten, emphasize, or prevent something. However, Shaykh al-Islam Ibn Taymiyyah holds that if you intended to effect the divorce upon the fulfillment of the condition, then you may retract it as long as the condition has not been met. But if you did not intend to effect the divorce, but rather to threaten, emphasize, or prevent, then no divorce occurs, and you are liable for an expiation for a broken oath (kaffarat yamin). If you swear by Allah that you will divorce her upon the occurrence of something, the divorce does not occur upon its happening, but you are liable for an expiation for a broken oath if you do not divorce her.