Red heifer
The unblemished red cow of the Hebrew Bible whose ashes were used for ritual purification.
Also: parah adumah, red cow
The nineteenth chapter of the Book of Numbers describes a red heifer without blemish that has never borne a yoke. It was to be burned outside the camp with cedar wood, hyssop and scarlet thread, and its ashes, mixed with water, were used to purify people who had touched a dead body. Jewish tradition, recorded in the Mishnah tractate Parah, holds that only nine such heifers were prepared from the time of Moses to the destruction of the Second Temple. The rule is often given as an example of a commandment whose reason lies beyond human understanding. The subject still draws study and interest today.