A Promise Unfulfilled
If someone gives you a promise they are bound. You can trust that they will be weighed down by the burden of the promise if unfulfilled. There are a few things we can do as receivers of a promise to lovingly help the situation.
Remind the person of their promise.
Support them in the fulfilling of the promise.
If neither of those work to achieve fulfillment, there is one final option. We may release them from the binding.
Leaving someone to their own devices might be seen as being unloving, lacking in justice, even cruel. But another way of looking at it is that a release of the binding is a form of forgiveness. Forgiveness for the unfulfilled promise.
This kind of forgiveness prevents the desire for condemnation, resentment, and bitterness from being planted and growing. The promise giver will still have to deal with their own heart. The guilt, shame, and potential fear of condemnation that comes from an unfulfilled promise may remain. But forgiveness is a way through all of that, too.
Grace in this situation allows us to truthfully say that a promise was unfulfilled, AND that the relationship between the promise giver and us is actually more important than the individual promise.