Rabbi Eliezer

The opening Mishnah in the tractate Parah tells that Rabbi Eliezer ben Hyrcanus ruled that the red heifer must be at least in her second year of life to work as a ritual purifier of those of have come into contact with a human corpse. The Midrash[1] tells that when Moses went up to Heaven, he heard HaShem saying this law in the name of "Eliezer, My son." Upon hearing this law, Moses asked of G-d that this Eliezer should be a descendent of himself. The Midrash tells that HaShem granted this request to Moses, which explains why the Torah calls Moses' son "the one named Eliezer.[2]" Indeed, the Rabbi Eliezer who said this law was a Levite[3], and very likely was a descendant of Moses[4].

[1] Tanchuma, Chukas §8 and Numbers Rabbah 19:&
[2] Exodus 18:4
[3] See Jerusalem Sotah 3:4
[4] For more information about Rabbi Eliezer, see Pirkei D'Rabbi Eliezer 1:1