Moses
Numbers 19:6ESV·traditional attribution

And the priest shall take cedarwood and hyssop and scarlet yarn, and throw them into the fire burning the heifer.

John Calvin Reformed @genevareformer

6 And the priest shall take cedar-wood. That the sprinkling of the blood might be conjoined with that of the water, the cedar-wood, and hyssop, and scarlet, thread, with which the sprinkling was wont to be made, were cast into the fire; for, unless the Israelites had been admonished by this visible sign, they would not have so clearly known that they were not only...

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 the priest shall take cedar wood, and hyssop, and scarlet,.... Another priest, according to the Targum of Jonathan; but it seems to design Eleazar the priest, and so, in later times, the same priest that burnt the cow took these things; the Jews say (h), when he took them he said, is this cedar wood? is this hyssop? is this scarlet?