"The pot calling the kettle black '' is a proverbial idiom that may be of Spanish origin of which English versions began to appear in the first half of the 17th century. The idiom is glossed in the original sources as being used of a person who is guilty of the very thing of which they accuse another and is thus an example of psychological projection.
pot calling the kettle black meaning in english
a person who is guilty of the very thing of which they accuse another