Those laws are not two. They are one. They have to do with not harming another person's property.
If you say something, and then break what you say, you have harmed another person who is depending on what you said, just as though you had harmed his body-property or other property.
There are two laws. They are the Golden Rule.
1. Love God above all things.
2. Love your neighbor as yourself.
If you don't believe in God, then you are damaging your family.
If you love your fellow human beings as yourself, you will attempt to do good for them in every way, not just by your agreements and contracts, nor simply by not harming their property directly, but in every way.