By Rav Jesse Horn
One may wonder why the laws of the Parah Adumah, the Red Heifer (laws of the Red Heifer teach how to attain purity), are recorded by the Torah now in the middle of Bamidbar (chapter 19). The Torah is not dealing with issues of purity those laws were taught in Vayikra.
This question is even more powerful according to Rashi (Shemot 15:25) who states that the laws of the Parah Adumah were previously taught in Marah (Shemot 15:25). Why record them now in Bamidbar and not in Shemot, when the Marah episode took place? Not only do these laws not fit into Bamidbar chronologically, they do not seem to fit in thematically either. Why place them here?
According to the aforementioned opinion of Rashi, Shabbat and Dinim (monetary legalities) were taught in Marah along with the Parah Adumah. Two questions must be asked. Firstly, why teach any laws in Marah? Why not just wait until Har Sinai and teach these three sets of laws with the rest of the Torah? Secondly, why these three sets of laws? For whatever reason, Hashem deemed it necessary to teach some laws in Marah; why these?
These three sets of laws (Shabbat, Parah Adumah and Dinim) were given in Marah as a sample or taste of what the Torah would be, as well as to test Bnei Yisrael so Hashem could see their response (Ramban Shemot 15:25). Based on this, one can understand why these three sets of laws were selected; they represent three categories of laws. Dinim represent logical laws. One can not imagine society without Dinim of one form or another. Shabbat represents laws that can be understood by man, but perhaps might not have been thought of a-priori. Lastly, Parah Adumah represents laws that cannot be understood by man. It is the paradigmatic example of a Chok (command beyond human reason). Hashem selected three sets of laws reflecting three categories of laws; intuitive, understood once commanded and completely dogmatic laws that are beyond man’s intellectual capability.
Because Parah Adumah represents the laws that capture the inability of man to understand Chukim (commands beyond human reason), and ultimately Hashem, it can be understood why it is recorded here in Bamidbar. Parah Adumah is the religious response to Korach’s rebellion’s claim (See Emet L’Yaakov on Bamidbar 19:2). The Parah Adumah embodies the devotion to Hashem and His commands regardless of whether they make sense to man. Parah Adumah is obeyed for one reason only, we believe it is Divine.
Korach’s rebellion rests upon the assumption that what makes sense to man, should be sought and obeyed. Korach argued that all men were holy and therefore should all be treated the exact same way. It follows that Aharon should be the sole high priest.
The Parah Adumah corrects that notion by underscoring that in this world we listen to Hashem, simply because He is Hashem. There is no better way to support that notion than with the archetypal Chok, Parah Adumah. Since there is no understood logical reason, there is only one reason to obey a Chok its accepted as the word of Hashem.