"A PROMISE MUST NEVER BE BROKEN"~ ALEXANDER HAMILTON 

I think this means that if you say your going to do something you have to keep it or meant it like for example "The boy who cried wolf" he was in charge of letting the people know that a wolf was coming and he would play around saying the wolf was coming when he wasn't and after a while he kept playing that prank on the people the people didn't believe him anymore so one day they boy was looking out and he saw the wolf heading there way and he yelled and screamed letting the people know that the wolf was coming and the people didn't believe him because he would lie a lot and right then and there the wolf ate him, that's why if your going to promise something make sure you are going to keep the promise you make this mostly goes for boys because they always promise you there going to do better and treat you better but they end up acting the same way or they may promise you that one day your going to get together but they don't keep there word they just lie and lie over and over again.