Sa di

Ch 08 On Rules For Conduct In Life - Maxim 10

Saadi Shirazi was a major Persian poet and prose write of the medieval period.

It is a mistake to accept advice from an enemy but permissible to hear it; and to act contrary to it is perfectly correct.

  Be cautious of what a foe tells thee to do
  Lest thou strike thy knee with the hand of pain.
  If he points thy way to the right like an arrow
  Deflect therefrom and take that to the left hand.