Zhōngyán nì'ěr (lìyú xíng).

忠言逆耳(利於行)。

Lit Honest advice [although it] is unpleasant to the ear (induces good conduct).

Note [Cf. Shǐ Jì: Liú Hòu Shì Jiā; the first part, often used alone as a chengyu: zhōngyán nì'ěr meaning: “the truth hurts,” or like the first part of a xiehouyu, paraphrases Hán Fēizǐ: Wài Chǔ Shuō Zuǒ Shàng; see also liángyào kǔkǒu above.]

Topics ADVICE chengyu CONDUCT Hán Fēizǐ HONESTY Liú Hòu Shì Jiā Shǐ Jì Wài Chǔ Shuō Zuǒ Shàng xiehouyu zhōngyán_nì_ěr