Nine Red Heifers were prepared from the time that the Jewish people were
commanded this mitzvah until the Second Temple was destroyed. The first was
prepared by Moses, the second by Ezra, and another seven were prepared from Ezra
until the Temple's destruction. The tenth Heifer will be prepared by Moshiach,
may he speedily be revealed, Amen, may it so be the will of G-d.
Mishneh Torah, Laws of the Red Heifer 3:4