Jiānchí zhè xiàng shìyè, shì tā yì yú xīn zhī suǒ shàn de xuǎnzé.
Sticking with this cause is, for him, "what his own heart holds to be good".
Tips
history
From Qu Yuan's (屈原) 《离骚》 (Warring States Chu): 亦余心之所善兮，虽九死其犹未悔 — 'This too is what my heart holds good — though I should die nine times, I would not repent of it.' The most quoted profession of moral self-integrity in classical Chinese poetry; often invoked in modern speeches (including by Xi Jinping) to signal unwavering commitment.
usage
Almost always cited together with 虽九死其犹未悔. 余 = classical 'I, my'; 兮 = Chu-ci rhythmic exclamatory particle; 所善 = 'that which is held good' (nominalized relative clause).
