Two Ways to Discern if a Mitzvah Stems from Kedushah
Thus, it is imperative to recognize the origin of a simple mitzvah. Did it come from the yetzer tov or perhaps, chas v’shalom, from the yetzer hara, who wants to prevent a Jew from serving Hashem on a higher level? A simple answer is for a Jew to consider whether the fulfillment of this mitzvah prevented him from serving Hashem with the increased intensity and vigor he originally planned on. This, however, is not always so easy to discern, since the yetzer hara tries to convince him that he is too weak and incapable of serving Hashem with increased vigor.
So, let us suggest two answers. Firstly, a person should ask himself whether or not the yetzer hara tried to prevent or oppose the performance of this mitzvah as it would for an important mitzvah such as the study of Torah. If so, this would indicate that the mitzvah stemmed from a place of kedushah. If, however, he does not sense any opposition from the yetzer hara relating to this mitzvah, he should suspect that perhaps the yetzer is offering him a minor mitzvah to cool off his enthusiasm, so that he will not end up doing something bigger and better—as suggested by the great Rabbi of Ropshitz, zy”a.
We can suggest that this method is alluded to in the opening words of our parsha: "שופטים ושוטרים תתן לך". After all, the chochmah, understanding, and intellect in a person’s brain are the “shoftim” with which he judges whether or not any act is one of kedushah or not. He is able to make this assessment if “shotrim”—enforcing officers within him—are required to compel the yetzer hara within him to allow him to perform this mitzvah. If he faces resistance from the yetzer hara, it is a sign that this mitzvah comes from a source of kedushah.
Secondly, Chazal teach us (Avos 4, 2): "שמצוה גוררת מצוה ועבירה גוררת עבירה"—one mitzvah leads to another mitzvah, and one aveirah leads to another aveirah. So, if this mitzvah is merely a device employed by the yetzer hara to reduce your enthusiasm to serve Hashem to an even greater degree, then it will not motivate you and lead to the performance of another mitzvah. After all, the aim of the yetzer here is to dissuade a Jew from performing more mitzvos and even bigger mitzvos.
