When does invalidation (Hanith) occur for an oath concerning divorce or manumission if the swearer acts in forgetfulness?

Primary text

Regarding divorce and manumission, invalidation occurs if the person swears not to do something and then does it while heedless. This is the apparent position of the Madhhab and was chosen by Al-Khallal and his companion, and it is the view of Abu Ubayd. In contrast, the view that one is not held liable for breaking an oath due to forgetfulness applies to all cases except divorce and manumission, where invalidation still occurs. Divorce and manumission are considered conditional statements that take effect upon the fulfillment of their condition, even without specific intent, similar to saying, "You are divorced if the sun rises," or, "if the pilgrim arrives."