God was utterly faithful with his covenant promises and he expects the same from us. Which is probably why He is constantly upset with Israel. My father used to tell me that the only things you really have in this life are your family and your word, and the latter is how you’ll be remembered.
When people break trust, it is nearly impossible to repair. And God wants to drive this home, so Leviticus ends with a list of how to re-claim people and possessions that have been dedicated, consecrated to the Lord.
Usually this was the result of a vow. Like when Hannah asks God for a child and she says that in return she will consecrate him to the Lord. Well, once Samuel was born, she essentially turned him over to the priests to serve in the Temple for the rest of his life.
God says no take-sy back-sies, BUT if you wish to reclaim (redeem) this person or thing consecrated (set apart) for the Lord, then there will be renumeration based on age and future earning potential in that day and time. These prices were not trivial, and for animals and inanimate possession there was a 20% surcharge on top of the market value. This was something to take seriously.
In the same way our word, our vow, our promise should be solid and meaningful. If we say we will do a thing, we have an obligation to actually do that thing. And not just because of the legacy that creates, or what people will think of us, but because we are called to be like the Lord. And He is faithful to the end.
Let’s be faithful in all our dealings as the Lord Himself is faithful.