What should I do if I accidentally swear to do something bad out of anger?

If you accidentally swear to do something bad out of anger, it is important to understand the context of oaths in Islam. The Qur'an states: Allah will not take you to task for that which is unintentional in your oaths, but He will take you to task for the oaths which ye swear in earnest. The expiation thereof is the feeding of ten of the needy with the average of that wherewith ye feed your own folk, or the clothing of them, or the liberation of a slave, and for him who findeth not (the wherewithal to do so) then a three days' fast. This is the expiation of your oaths when ye have sworn; and keep your oaths. Thus Allah expoundeth unto you His revelations in order that ye may give thanks. 5:89

This verse indicates that if the oath was uttered unintentionally or in anger, you are not held accountable in the same way as for deliberate oaths. However, if you find yourself in a situation where you have sworn an oath seriously, the expiation involves feeding the needy or fasting if you cannot fulfill the oath.

Additionally, the Prophet Muhammad ﷺ taught that if someone swears to do something that leads to sin or harm, they should break that oath and seek to do what is better. Thus, if you have sworn an oath out of anger, it is advisable to expiate for it and turn towards actions that align with righteousness and goodness.