You can apologize for words. You can’t collect them back.

An apology repairs the relationship, which is real and worth doing. What it cannot do is remove the sentence from the other person’s memory, where it now sits alongside the knowledge that you thought it. The damage is not only the hurt, it is the new information about what is in you.

In an argument, the rule that saves the most is not saying the cruelest true thing you can think of. You will want to. Getting up and coming back in ten minutes costs you nothing and keeps the sentence unsaid.