Water for Impurity
WATER FOR IMPURITY (מֵ֥י נִדָּ֖ה; waters of impurity; KJV WATER OF SEPARATION).
“Water for impurity” (Num 19:9, 13, 20, 21; 31:23) was a purifying agent for a person or thing that had been defiled by contact with the dead as well as for other reasons.
The ashes of a red cow were added to “running water” which was then applied to the defiled object. The animal used in this ceremony had to be a female of reddish-brown color, without any physical defects, and one that had never borne a yoke. The burning of the cow took place “without the camp,” the whole animal, even the blood, with the exception of some that was used in sprinkling toward the front of the tent, being reduced to ashes. This distinguishes the ceremony from the Levitical ritual sacrifice. A piece of cedar wood and a bunch of hyssop bound with a scarlet cloth were burned with the cow.
The ashes were kept “outside the camp” in a clean place until they were mixed with the spring water for the specific ceremonies of purification. This “water for impurity” was applied to the defiled person or object by being spilled over it, or sprinkled with branches of hyssop. The ceremony was performed on the third and seventh days after which the person was cleansed, bathed, and had his garments washed, which restored him to the community from which his defilement had excluded him. The account in Numbers 31:13 had to do with defiled objects taken in battle.