Translation:My nose is running a lot.
From urban dictionary (maybe not everyone, including me, knows this proverb)
An expression that is said when one accuses another person of that which they are equally guilty of.
Many years ago, people used to cook over an open flame using copper kettles and iron pots. The copper kettles were usually polished after every use whereas the iron pots were not and remained blackened from the soot from previous cookings. Well someone got the idea that if the iron pot were alive and it looked at a nearby copper kettle, it would see a black image. The iron pot believes it sees the image of the copper kettle when in reality, because the copper kettle was polished, what the iron pot was seeing was a reflection of itself. This symbolic phrase became associated with hypocrisy. An accuser blames someone else for having a fault when the accuser has the same fault.