John Calvin Reformed @genevareformer

3 And ye shall give her unto Eleazar. A clear distinction is here made between two offerings; for the people are not permitted to kill the heifer, but this is the peculiar office of the priest. Thus the people offered vicariously by the hand of the priest; and in this way also at present, although we set Christ before God’s face in order to propitiate...

Matthew Henry Presbyterian @wholebiblehenry

We have here the divine appointment concerning the solemn burning of a red heifer to ashes, and the preserving of the ashes, that of them might be made, not a beautifying, but a purifying, water, for that was the utmost the law reached to; it offered not to adorn as the gospel does, but to cleanse only.

Commenting on Numbers 19:1-10

John Gill Reformed Baptist @doctorgill

And ye shall give her unto Eleazar the priest,.... The son of Aaron; the Sagan of the priests, as the Targum of Jonathan calls him, the second or deputy priest; it was not to be given to Aaron, that he might not be defiled, though but for a small time, that so he might not be hindered in his office at all; but to Eleazar...