و من كتاب له عليه السلام إلى عبد الله بن العباس و كان ابن عبَّاس يقول ما انتفعت بكلام بعد كلام رسول الله- صلى اللّه عليه و آله- كانتفاعي بهذا الكلام
اما بعد فان المر قد یسره درک ما لم یکن لیفوته و یسووه فوت ما لم یکن لیدرکه فلیکن سرورک بما نلت من آخرتک و لیکن اسفک على ما فاتک منها و ما نلت من دنیاک فلا تکثر به فرحا و ما فاتک منها فلا تاس علیه جزعا و لیکن همک فیما بعد الموت
A Letter from Imam Ali (a.s)
[Ibn Abbas says that once Imam Ali (a) advised him in the following words, and except for the advice of the Holy Prophet (s) no advice has been so beneficial to him as this.]
After glorifying Allah and praising the Holy Prophet (s) let it be known to you, Ibn Abbas, that a man feels very happy if he achieves a thing without understanding that it would have ultimately come to him and he would not have missed it, and sometimes he feels sorry at not acquiring a thing which was not destined for him and which he could never have acquired. Only such things as will earn for you a reward in the next world should please you and you should only feel sorry for losing rewards of the next world. If you attain worldly pomp and pleasures then let not your happiness increase along with every enhancement of such pleasure and if you lose any of these pleasures then do not feel sorry at the loss because you must only feel sorry at the loss of such things as will be of use to you in the next world.