Ramban, a 12th century Jewish Biblical Commentator

Doni Bloomfield sends me this passage:

Set aside a sum of money that you will give away if you allow yourself to be angered. Be sure that the amount you designate is sufficient to force you to think twice before you lose your temper… (Ramban: A letter for the Ages translated by Avrohom Chaim Feuer Reishit Chochmah, Shaar Ha'anavah Chapter 3)

The link to the source is here.