A person who says “yes” or “no” within the context of a promise, yet does not really mean these words is being deceitful. Leading others to believe that you are committed to your promise, when in fact you are not, is a form of lying. This lie becomes consolidated the moment the promise is broken.
Unfortunately, so many people make casual promises, taking their own word very lightly. They do not have the integrity to say only what they mean, and to follow up on their words through actions. People who are not serious about their promises violate the 9th commandment by deceiving other people into believing in their false intent and false commitment.
If you want to be a person of integrity, ensure that you are always careful when making promises. Do not risk misleading others into believing in you when you yourself are unsure. In times of uncertainty, it is better not to promise at all.