A red heifer was to be chosen, the colour of the animal pointing to the hue of blood. The heifer was to be free from blemish, a type of vigorous and prolific life. The charge of the sacrifice was to be given to Eleazar the priest, for the high-priest himself might not undertake a duty the performance of which caused uncleanness. The ceremonies must take place not only outside the tabernacle court, but outside the camp, that the intensity of the uncleanness to be transferred to the animal and purged by the sacrifice may be clearly understood. The heifer being slain, the priest takes of its blood and sprinkles it towards the tent of meeting seven times, in lieu of the ordinary sprinkling on the altar. The whole animal is then burnt, and while the flame ascends the virtue of the residuent ashes is symbolically increased by certain other elements. These are cedar wood, which was believed to have special medicinal qualities, and also may have been chosen on account of the long life of the tree; some threads of scarlet wool which would represent the arterial blood, instinct with vital power; and hyssop which was employed in purification. The priest, having presided at the sacrifice, was to wash his clothes in water and bathe his flesh and hold himself unclean till the even. The assistant who fed the fire was in like manner unclean. These were both to withdraw; and one who was clean was to gather the ashes of the burning and, having provided some clean vessel within the camp, he was to store up the purifying ashes for future use by the people. Finally, the person who did this last duty, having become tainted like the others, was to wash his clothes and be unclean for the day. The ashes were to be used by mixing them with water to make "water for pollution"; that is, water to take away pollution. Special care was to be exercised that only living water, or water from a flowing stream, should be used for this purpose. It was to be applied to the defiled person, vessel, or tent, by means of hyssop. But, again, the man who used the water of purification in this way was to wash his clothes and be unclean until even.