"A promise must never be broken."

"A promise must never be broken."

Alexander Hamilton 

I think that this quote means you should never break a promise. I also think that  this quote means you should keep your word. An example can be: like saying " I'll never do drugs." and you never do them, that's keeping your word. A other example can be if: you say "I'll do  my homework everyday." and you don't do it then you're not keeping your promise.