Iron heart and iron gall
Tongxintiedan, a Chinese idiom, Pinyin is t ó NGX ī NTI ě D ǎ n, which describes a person's firm will. From Xiao Shulan.
Idiom explanation
To describe a firm will.
Idioms and allusions
The second fold of Jia Zhongming's Xiao Shulan in Ming Dynasty: "every scholar's eyes have been greedy since ancient times. It's not like he has such a strong heart here."
Discrimination of words
As an object or attribute; used in figurative sentences
Iron heart and iron gall
take advantage of one 's position and power - yǐ guān xié shì
one keeps his pearl in the bosom and the country goes to ruin - huái bǎo mí bāng
use one 's position to get even with another person for a private grudge - gōng bào sī chóu