Run to Do All Mitzvos—Major or Minor
In this manner, let us interpret the following Mishnah (ibid.): "בן עזאי אומר, הוי רץ למצוה קלה כבחמורה ובורח מן העבירה, שמצוה גוררת מצוה ועבירה גוררת עבירה, ששכר מצוה מצוה ושכר עבירה עבירה". Ben Azai says: One should run to perform a minor mitzvah just as he would to a major mitzvah, and he should flee from performing an aveirah; for one mitzvah leads to another mitzvah, and one aveirah leads to another aveirah. For, the reward for a mitzvah is a mitzvah, and the reward for an aveirah is an aveirah. Based on what we have learned, a person might be leery and hesitant to perform a minor mitzvah out of concern that it might have been presented to him by the yetzer hara. To dismiss this concern, Ben Azzai urges us: Run to perform a minor mitzvah just as you would to a major mitzvah.
And if you are still worried that this mitzvah did not originate from a source of kedushah but was made available to you by the yetzer hara, remember that one mitzvah leads to another mitzvah, and one aveirah leads to another aveirah; apply this criterion to discern the origins of the mitzvah. In other words, if it is apparent to you that this mitzvah inspires you to perform other mitzvos, this proves that it originated in kedushah. If, however, you see that this mitzvah cooled down your enthusiasm to perform other mitzvos, it is apparent that it came from the yetzer hara.
I believe that both of these methods are hinted to in tefilas Arvis (Hashkiveinu): "והסר שטן מלפנינו ומאחרינו"—and remove the adversary from before us and behind us. We can interpret this as a request to HKB”H to help us discern the origin of the mitzvah before we actually perform it. Enable us to recognize if the yetzer hara is urging us to perform this mitzvah to accomplish its goal by sensing if it opposes this mitzvah or not. But even if we fail to make this distinction prior to performing the mitzvah, we also request that Hashem will help us by removing the adversary behind us—i.e., after doing the mitzvah—by scrutinizing the consequences of the mitzvah. Did it enhance our desire to do mitzvos or diminish our desire?
