Al-Imam Ali (p.b.u.h), said:

Hadith n. 118:
Amir al-mu’minin, peace be upon him, said: To miss an opportunity brings about grief.

Hadith n. 119:
Amir al-mu’minin, peace be upon him, said: The example of the world is like a serpent. It is soft to the touch but its inside is full of venom. An ignorant person who has fallen into deceit is attracted towards it, but a wise and intelligent man keeps on his guard against it.

Hadith n. 120:
Amir al-mu’minin, peace be upon him, was asked about the Quraysh, when he replied: As for Banu Makhzum, they are the blossoms of the Quraysh. It is delightful to talk to their men and to marry their women. As for Banu ‘Abd Shams, they are farsighted and cautious about all that is hidden from them. As for ourselves (Banu Hashim), we spend whatever we get and are very generous in offering ourselves in death. Consequently, those people are more numerous, more contriving, and more ugly, while we are more eloquent, well-wishing, and handsome.

Hadith n. 121:
Amir al-mu’minin, peace be upon him, said: What a difference there is between two kinds of actions: an act whose pleasure passes away but its (ill) consequence remains, and the act whose hardship passes away but its reward stays.

Source: https://www.al-islam.org/nahjul-balagha-part-2-letters-and-sayings