the pot calling the kettle black

"the pot calling the kettle black" is a metaphorical idiom that means a person is criticizing or accusing someone of a fault or behavior that they themselves possess. It implies hypocrisy, as the speaker is pointing out a similarity between themselves and the person they are criticizing, despite the lack of self-awareness. The phrase originated from the fact that both a pot and a kettle, when heated, become black or darkened on the surface, making it ironic for one to criticize the other for a trait that they both share.