Numbers 31:21

“And Eleazar the priest said unto the men of war, which went to the battle, etc.] To all the soldiers, officers, and common men: this is the ordinance of the law, which the Lord commanded Moses; concerning the purification of unclean persons and things, hereby confirming what Moses had said.”

“Num 30:16 Numbers 31:23”

“To this end Eleazar, whose duty it was as high priest to see that the laws of purification were properly observed, issued fuller instructions with reference to the purification of the different articles, in accordance with the law in ch. 19. למּלחמה הבּאים, those who came to the war, i.e., who went into the battle (see at Num 10:9). "The ordinance of the law:" as in Num 19:2. The metal (gold, silver, copper, tin, lead), all that usually comes into the fire, i.e., that will bear the fire, was to be drawn through the fire, that it might become clean, and was then to be sprinkled with water of purification ( Num 19:9); but everything that would not bear the fire was to be drawn through water. -…”