“…Who has counted the dust of Yaakov?…” – Bamidbar 23:10

מִי מָנָה עֲפַר יַעֲקֹב – במדבר כג, י

Bilaam’s plot to curse the Jewish people was foiled when G-d forced him to bless and praise them instead. Describing the Jewish people’s endearment to G-d, Bilaam said, “Who can count the dust of Yaakov?” According to one interpretation brought by Rashi, Bilaam was saying, “Even the mitzvos they observe with dust are innumerable!”For example, says Rashi, the Jewish people are commanded not to harness an ox and a donkey together when plowing the earth (Devarim 22:10), not to sow their fields with a mixture of seeds (Vayikra 19:19), to use the dust-ashes of the red heifer for purification, and to use the dust in the examination of a sotah, a woman suspected of infidelity.

The Midrashim enumerate many more mitzvos associated with dust, yet Rashi names these four in particular. In doing so, Rashi alludes that the mitzvos involving dust are not only numerous, they are actually innumerable.

The first two examples that Rashi cites are agricultural prohibitions. The Jewish people’s primary occupation in Biblical times was farming, thus their fulfillment of the prohibitions related to plowing and planting was regular and constant—each time a person plowed or planted his field in the permissible manner.

Likewise, the mitzvos involving the ashes of the Parah Adumah and the dirt used to examine the Sotah contain an element of immeasurability; their fulfillment is not a one-time occurrence. This is because in addition to using the Parah Adumah ashes for purification, we are commanded to set aside a portion of the ashes “as a keepsake for the congregation of Israel” (Bamidbar 19:9). Hence, the mitzvah is fulfilled constantly—as long as some ashes remain in existence. The same is true of the dirt used in the examination of the Sotah. Its significance as “mitzvah-dust” extends throughout the duration of its use, and for as long as it is effective. This includes the effects of the sotah-waters on the woman’s future—“she is cleansed and she will bear seed” (Bamidbar 5:28); i.e. the dust of the sotah-waters restores her marriage and infuses it with continuous blessing.

Considering the Jewish people’s “incalculable” observance of the mitzvos, said Bilaam, no curse could possibly affect them.

—Likutei Sichos, vol. 38, pp. 92-96