353. Amīr al-mu’minīn, peace be upon him, said: The greatest defect is to regard that defect (in others) which is present in yourself. 
 What worse defect can there be than that a man should criticise those defects in others which exist in himself. The requirement of justice is that before casting one’s eye on the defects of others one should look at his own defects and realize that a defect is a defect whether it be in others or in oneself.
A Persian couplet says : Looking at other’s defects is neither property nor manliness. Better look at your own self since you are full of defects.