This is the decree of the Torah that Hashem commanded, saying: Speak to the Jewish people and let them take for you [Moshe and Aharon] a cow that is entirely red, unblemished, upon which no yoke has been placed…take it outside the encampment and slaughter it….and burn it…and the Kohen shall take cedar wood, hyssop, and a crimson thread, and cast it into the burning cow…One who touches a corpse shall be contaminated for seven days. He shall be purified with [the ashes of the red cow]… (Bamidbar Ch. 19).

PREFACE

The most severe form of impurity is that which rests upon corpses. The only way to purify a person who has become contaminated with corpse impurity is to sprinkle upon him the ashes of a Parah Adumah (red cow) on the third and seventh days after his impurity. Even if the first sprinkling is delayed, the second sprinkling cannot be less than four days afterward.

The Torah calls the ritual of Parah Adumah a "chok," meaning it is a decree without a known reason. Rabbi Menachem Recaniti explains this as follows: “Know that the esoteric idea behind the Parah Adumah is exceedingly hidden, and the Sages say that it was only revealed to Moshe. This does not mean that we do not know the reason for this mitzvah at all, but rather that there is one aspect of this mitzvah that only Moshe understood, namely, why it purifies those upon whom it is sprinkled but contaminates those who touch it. About this Shlomo proclaimed in Koheles (7:23), ‘I said that I would comprehend it, but it is distant from me.’”

THE CALF AND THE COW

Hashem intended for mankind to be Divine and live forever, but Adam and Eve sinned and brought death to the world. The Jewish people were restored to the original state of Divinity when they received the Torah at Mount Sinai, but they immediately lost it when they sinned with the Golden Calf. The introduction of death through the sin of the Golden Calf brought impurity to the world as well, for the most severe form of impurity rests on corpses.

Thus, the idea behind the ritual of Parah Adumah, which purifies a person who is contaminated with corpse impurity, is that it reverses the effects of the Golden Calf. In the words of the Sages, Hashem commanded us to bring a cow to rectify the sin that involved a calf in the same way a mother cleans up after her child.

A RED COW BECOMES WHITE ASHES

The cow is entirely red, a color that is symbolic of sin and impurity, and which resembles the reddish-golden color of the Golden Calf. The Parah Adumah is incinerated and becomes white ashes, a color that symbolizes purity. By burning the Parah Adumah, the ashes become invested with the power of purification.

WITHOUT A BLEMISH AND WITHOUT A YOKE

The Parah Adumah must be unblemished because the Jewish people were unblemished before the sin of the Golden Calf, and the Parah Adumah restores a person to a state of “unblemished” purity. It cannot bear a yoke, because the Jewish people cast off the yoke of Heaven when they worshipped the Golden Calf.

THE THREE ADDED COMPONENTS

The Parah Aduamh is burned in the same way Moshe burned the Golden Calf. We cast cedar wood and hyssop into the fire because the cedar is tall and the hyssop is lowly, and this alludes that one needs to humble himself in order to repent and become pure. A crimson thread is placed in the fire, symbolizing that even if a person is red with sin he can become purified. These three components — the cedar, hyssop, and crimson thread — allude to the three thousand worshippers of the Golden Calf, and to the three punishments to which the people were subjected.

THE PLACE AND TIME

Since the Parah Adumah is associated with impurity, it must be burned outside the Beis HaMikdash, unlike the offerings that must be brought specifically within the Beis HaMikdash.

The purification process takes one week, in which water that has been sanctified with the ashes is sprinkled on the contaminated person on the third and seventh day after he became contaminated. These two days symbolize purity and sanctity because they correspond to the third day of the week on which Hashem created springs [that purify], and the seventh day of the week that He sanctified as Shabbos.

A LESSON FOR ALL TIME

In closing, we may add that the mitzvah of Parah Adumah causes us to contemplate that death and other imperfections in this world are only because of sin. It is therefore within our power to repent and restore our lives and the world to purity and perfection.

Sources: Rashi,Midrash HaGadol,Pisron Torah,Bamidbar Zutta, Torah Shleimah,Recaniti, Alshich.