The promise of miracles as evidence of faith

 

In the SD
Hello Rabbi,
In our weekly torah portion, we find a promise of a miracle if they observe Shemitah properly.
The Rabbi brought such evidence in the fifth booklet and elsewhere as something that strengthens belief in the tradition, but I do not recall anywhere where he conducted a sufficient discussion of them.
Could the Rabbi expand on the subject for once? Especially since it is not known that we have no information that the promises were fulfilled… and perhaps sometimes the opposite.