If you criticise, the words you speak turn against you and fulfill their negative repercussions on you and not on your object of criticism. Watch your lips, literally!
Mat 12:36-37 KJV
36 But I say unto you, That every idle word that men shall speak, they shall give account thereof in the day of judgment.
37 For by thy words thou shalt be justified, and by thy words thou shalt be condemned.