Moses
Numbers 19:20ESV·traditional attribution

“If the man who is unclean does not cleanse himself, that person shall be cut off from the midst of the assembly, since he has defiled the sanctuary of the LORD. Because the water for impurity has not been thrown on him, he is unclean.

Matthew Henry Presbyterian @wholebiblehenry

Directions are here given concerning the use and application of the ashes which were prepared for purification. they were laid up to be laid out; and therefore, though now one place would serve to keep them in, while all Israel lay so closely encamped, yet it is probable that afterwards, when they came to Canaan, some of these ashes were kept in every town, for...

Commenting on Numbers 19:11-22

John Gill Reformed Baptist @doctorgill

But the man that shall be unclean,.... By touching any dead body, bone, or grave: and shall not purify himself; with the water of purification: that soul shall be cut off from among the congregation: See Gill on Num 19:13.

Keil & Delitzsch Lutheran @keilanddelitzsch

Num 19:17-20 Ceremony of purification. They were to take for the unclean person some of the dust of the burning of the cow, i.e., some of the ashes obtained by burning the cow, and put living, i.e., fresh water (see Lev 14:5), upon it in a vessel.

Commenting on Numbers 19:17-20