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

When you gain power over your adversary pardon him by way of thanks for being able to overpower him.

The most helpless of all men is he who cannot find a few brothers during his life, but still more helpless. is he who finds such a brother but loses him.

When you get (only) small favours do not push them away through lack of gratefulness.

He who is abandoned by near ones is dear to remote ones.

Every mischief monger cannot even be reproved.

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