accuse (one) of (something)
To blame one for a crime or wrongdoing. I can't believe he would accuse me of stealing money out of his wallet. Don't accuse him of lying without any evidence.
he who excuses himself accuses himself
By apologizing, one admits that they have done something wrong. No, if you apologize to Mom, then she'll know that you were the only who scratched up her car. He who excuses himself accuses himself!
accuse someone of something
to charge someone with a crime, a violation of rules or instructions, or doing something wrong. Please don't accuse me of forgetting to lock the door.
He who excuses himself accuses himself.
Prov. By apologizing for something, you admit that you did it. Maybe I should tell my boss I'm sorry for breaking the copy machine. On the other hand, he who excuses himself accuses himself.