Purification of the Ritually Impure

(Book of Numbers 19:1 - 19:22)
Jehovah instructed Moses and Aaron, "Tell the Israelites that this is a ritual required by Jehovah: they must bring to you a red heifer [female calf] that is without flaw or defect, and has never been yoked.  You should deliver it to Eleazar so that it can be taken outside of the camp and slaughtered in his presence.  He will take some of its blood on his finger and sprinkle it 7 times in front of the Tabernacle.  In his sight, the heifer should be burned, its hide, meat, blood, and internal organs.  Onto the fire burning the heifer the priest should throw a length of cedar wood, a hyssop branch, and some wool yarn dyed scarlet.

"The priest must wash his clothes and bathe.  He may then return to camp, but will be ritually impure until after sunset.  The man who burns the heifer must also wash his clothes and bathe, and he, too, will remain ritually impure until after sunset.  Someone who is ritually pure will collect the ashes of the burned heifer and deposit them in a ritually pure area outside of camp.  These will be kept for the Israelite community to use with the cleansing water that is a part of the purification ritual.  The person who collects the ashes of the heifer must wash his clothes and bathe and will remain ritually impure until after sunset.

"This will be a permanent law for the Israelites and for foreigners residing among them: those who have contact with a dead body will remain ritually impure for 7 days.  They must purify themselves with water on the 3rd and the 7th days.  If they do not do so, they cannot reclaim ritual purity, and if they do not properly purify themselves after having contact with a dead body, then they defile the Tabernacle of Jehovah and must be banished from the community of Israel.  If the cleansing water has not been sprinkled upon them, they are impure and the impurity will remain with them.

"This is the law applicable when someone dies in a tent: anyone who has come into the tent where the dead person lies or who was in the tent when the person died will be ritually impure for 7 days. Every open container there without a lid or cover is also ritually impure.  Anyone who touches a dead body in an open field, whether the person has been killed or died from natural causes, and anyone who touches a human bone or a grave will be ritually impure for 7 days. 

"To cleanse the impure, ashes from the purification ritual should be placed in a jar and fresh water poured over them.  A man who is ritually pure should dip a hyssop branch into the water and sprinkle it on the tent, its furnishings, and on all the people who were there, upon the person who touched the human bone, the person who touched the dead body of someone who was killed or died naturally, or someone who touched a grave.  This person who is ritually pure should sprinkle the water on those who are impure on the 3rd and 7th days.  Then, on the 7th day, those who are being cleansed should wash their clothes and bathe, and after sunset they will cleansed of their defilement.

"But those who become defiled and do not purify themselves, are to banished from the community because they have defiled the Tabernacle of Jehovah.  Since the cleansing water has not been sprinkled upon them, they remain impure.  This is a permanent law for the people.  Those who sprinkled the purifying water must afterwards wash their clothes, and anyone who may touch the water used for purification will remain ritually impure until after sunset.  And anyone and anything the defiled person may touch will remain ritually impure until after sunset."

Notes
1. While there may be symbolism in cleansing by the sprinkling of water mixed with the ashes of a slaughtered heifer, it is hard for the rational modern mind to find any cause-and-effect relationship here, as it is hard to see anything in the concept of ritual purity and purification save primitive superstition and rank nonsense.  But it is easy to understand the bottom line: if you don't observe the common customs of the community, you will, at the very least, be kicked out of the community.

2. One wonders how much time and energy and resources were expended by the ancient Israelites upon the preservation and recovery of ritual purity.  It did serve several important purposes, though -- making worshipers ever conscious of the laws placed upon them by Jehovah, as well as making the priesthood indispensable and endowing it with the power to interfere in practically every aspect of life.