The best answer to anger is silence.

Related:

• In the midst of great joy do not promise a man anything;
  in the midst of great anger do not answer a man's letter...
• Invalids live longest.
  German...
• A shroud has no pockets.
  German...
• Where there are no swamps there are no frogs.
  German...
• The most effective answer to an insult is
  silence...
• It is not always advantageous to attack your opponent.
  German...
• To change and to improve are two different things. -
  German...
• Charity sees the need, not the cause.
  German...