The example of those who have understood this world is like those travelers who, being disgusted with drought-stricken places, set off for greenery and a fruitful place. Then they endure difficulties on the way, separation from friends, hardships of the journey and unwholesome food in order to reach their fields of plenty and place of stay. Consequently, they do not feel any pain in all this and do not regard any expenditure to be waste. Nothing is more lovable to them than what takes them near their goal and carries them closer to their place of stay.
[In contrast to the first group], the example of those who are deceived by this world is like the people who were in a green place but they became disgusted with it and went to a drought-stricken place. Therefore, for them nothing is more detestable or abominable than to leave the place where they were to go to a place which they will reach unexpectedly and for which they are heading.
(Selected from Ali ibn Abi Talib’s letter to his son)
Reference: Nahjul Balagha; Letter 31: https://www.al-islam.org/…/letter-31-advice-one-his…