Moses told the Jewish people that if they would be careful to perform all of G d’s commandments, even the seemingly minor ones, G‑d would provide them with all the material means that they would need to fulfill His will.
True Reward
וְהָיָה עֵקֶב תִּשְׁמְעוּן אֵת הַמִּשְׁפָּטִים הָאֵלֶּה וּשְׁמַרְתֶּם וַעֲשִׂיתֶם אֹתָם וגו': (דברים ז:יב)
[Moses told the Jewish people,] “If you heed [G‑d’s] ordinances, safeguard them, and perform them. . . . ” Deuteronomy 7:12

If G‑d were to bestow His goodness on us even when we do not deserve it, He would not be doing us any favors. First, we would feel like little children whose parents overlook their infantile behavior because adult behavior cannot be expected of them. Worse yet, it would undermine our belief in Divine justice. We would thus live lives of shame and confusion.

The rewards for observing G‑d’s commandments are so great that they are out of proportion to the effort required to fulfill them. Nonetheless, for the above-stated reasons, G‑d made the bestowal their reward dependent upon our efforts, and the bestowal of their infinite reward dependent upon effort that specifically mirrors their infinite, unlimited nature.

Therefore, we must take care to fulfill the seemingly less-important commandments with the same devotion with which we fulfill the seemingly more-important ones. This shows that what matters to us is that G‑d wants us to observe these commandments, not our own evaluation of which ones are important. G‑d then bestows His goodness upon us beyond the strict dictates of what we have earned.1