Fundamentally, the commandment of the red heifer-sprinkling its ashes upon the impure to purify them, is most unusual. One of its laws, however, expresses an important and powerful lesson. When the ashes of a new red heifer are prepared, the ashes of the new cow are mixed with the old ones. This was done with all the red heifers - from the first red heifer of Moses to the heifer to be prepared by Moshiach in the near future.
This continuity that exists in this commandment is not really unique though; it’s representative of the story of the Jewish people in general. Our tradition goes all the way back to Moses and will continue until the arrival of Moshiach and beyond.