jūn​zi​bào​chóu​shí​nián​bù​wǎn

revenge is a dish best served cold

君子报仇,十年不晚 君子報仇,十年不晚 jūn​zi​bào​chóu​shí​nián​bù​wǎn
revenge is a dish best served cold
Literally "for a person of noble character to take revenge, ten years is not too late"; implies that it is better to wait for the perfect moment to settle a score than to act rashly.