千金

一诺千金是中华民族自古崇尚的美德，既然当面向别人许下了庄严诺言，就必须信守到底。

yí nuò qiān jīn shì zhōng huá mín zú zì gǔ chóng shàng de měi dé, jì rán dāng miàn xiàng bié rén xǔ xià le zhuāng yán nuò yán, jiù bì xū xìn shǒu dào dǐ.

A promise worth a thousand pieces of gold is a virtue that the Chinese nation has admired since ancient times. Since you have made a solemn promise to others in person, you must keep it to the end.

他平时生活节俭但在公益捐款时却从不小气，总是一掷千金支援灾区。

tā píng shí shēng huó jié jiǎn dàn zài gōng yì juān kuǎn shí què cóng bù xiǎo qì, zǒng shì yī zhì qiān jīn zhī yuán zāi qū.

He usually lives a frugal life but is never stingy when it comes to donating money to charity, always spending large sums of money to support disaster areas.