A promise is a debt.
Many people make promises without any consideration for their words. Their word is absolutely meaningless to them. A promise from them is to be taken with a grain of salt. It usually means little more than they are in a desperate state at the time and they are willing to say anything to get whatever it is that they need for the moment. Once they have what they are after, their promise is quickly forgotten. They never consider that a promise is a debt, after all, who is going to force them to live up to their word?
The warrior, on the other hand, is a man of his word. If he promises that he will do something, he does it, period. He doesn’t make empty promises just to get his way, this would be dishonorable. He takes his word of honor seriously.
To him, a promise is indeed a debt, and a debt that will be repaid. Warriors feel honor bound to make their word good. People who make empty promises lose the respect of those around them, and the warrior realizes this.
He is not willing to compromise his word or the respect that his character affords him. To the man of honor, a promise means as much as a written contract that is signed and notarized. His word is good whether it is written on paper or written on the wind. Your promise is your word of honor.
It should not matter whether or not your promise is legally binding in a court of law. The warrior lives by a higher law than the law of the land; he lives by the law of honor.