Moses
Numbers 19:2KJV·traditional attribution

This is the ordinance of the law which the LORD hath commanded, saying, Speak unto the children of Israel, that they bring thee a red heifer without spot, wherein is no blemish, and upon which never came yoke:

John Calvin Reformed

2 This is the ordinance of the law. Because it could not but occur that, whilst the faithful were engaged in the world, they should often contract some pollution by their contact with its many impurities, the composition of the water is here described, by the sprinkling of which they might wash away, and expiate their uncleanness: and then certain kinds of pollution are specified, whereof the purification is required.

Matthew Henry Presbyterian

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

This is the ordinance of the law which the Lord hath commanded,.... By which it appears, that this law was not of the moral, but of the ceremonial kind, being called an ordinance, a statute, a decree of God, the King of kings; and which was founded not on any clear plain reason in the thing itself, but in the will of God, who intended...