When someone critises or disagrees with you, a small ant of hatred and antagonism is born in your heart. If you do not squash that ant at once, it might grow into a snake, or even a dragon.
RumiWhat the sayer of praise is really praising is himself, by saying implicitly, My eyes are clear." Likewise, someone who criticizes is criticizing himself, saying implicitly, "I can't see very well with my eyes so inflamed.
Rumi