Keep your word and keep your word.
The antonym is not a promise.
In a word, even four horse-drawn cars are hard to catch up with. When you say something, you can't take it back. You must keep your promise.
The source "The Analects of Confucius Yan Yuan": "The master is also a gentleman, which is embarrassing."
"Deng Xi's Biography": "A word is inconsistent, and the horse cannot be chased; In a hurry, the horse can't reach. "
A courageous person ~, there is no reason to repent! (The third fold of Li Yuan Shouqing's "Five Yuan Blow")