The red heifer (Hebrew: פָרָה אֲדֻמָּה; para adumma), also known as the red cow, was a cow brought to the priests as a sacrifice according to the Hebrew Bible, and its ashes were used for the ritual purification of Tum'at HaMet ("the impurity of the dead"), that is, an Israelite who had come into contact with a corpse.
The Book of Numbers stipulates that the cow must be red in color, without blemish, and it must not have been used to perform work. (Numbers 19:2) The heifer is then ritually slaughtered (Numbers 19:3) and burned outside of the camp (Numbers 19:3–6). Cedar wood, hyssop, and wool or yarn dyed scarlet are added to the fire, and the remaining ashes are placed in a vessel containing pure water. (Numbers 19:9)
In order to purify a person who has become ritually contaminated by contact with a corpse, water from the vessel is sprinkled on him, using a bunch of hyssop, on the third and seventh day of the purification process. (Numbers 19:18-19)
The Mishnah, the central compilation of Rabbinic Oral Law, the oral component of the written Torah, contains a tractate on the red heifer, tractate parah ("cow") in Seder Tohorot, which explains the procedures involved. The tractate has no existing Gemara, although commentary on key elements of the procedure is found in the Gemarah for other tractates of the Talmud. According to Mishnah Parah, the presence of two black hairs invalidates a red heifer, in addition to the usual requirements of an unblemished animal for sacrifice.
There are various other requirements, such as natural birth. The water must be "living" i.e. spring water. This is a stronger requirement than for a ritual bath. Rainwater accumulated in a cistern is permitted for a mikveh but cannot be used in the red heifer ceremony.
The Mishnah reports that in the days of the Temple in Jerusalem, water for the ritual came from the Pool of Siloam. The ceremony involved was complex and detailed. To ensure complete ritual purity of those involved, care was taken to ensure that no one involved in the red heifer ceremony could have had any contact with the dead or any form of tumah, and implements were made of materials such as stone, which in Jewish law do not act as carriers for ritual impurities. The Mishnah recounts that children were used to draw and carry the water for the ceremony, children born and reared in isolation for the specific purpose of ensuring that they never came into contact with a corpse:
There were courtyards in Jerusalem built over [the virgin] rock and below them a hollow [was made] lest there might be a grave in the depths, and pregnant women were brought and bore their children there, and there they reared them. And oxen were brought, and on their backs were laid doors on top of which sat the children with cups of stone in their hands. When they arrived in Shiloah [the children] alighted, and filled [the cups with water], and mounted, and again sat on the doors— Mishna Parah 3:2
According to the Mishnah, the ceremony of the burning of the red heifer took place on the Mount of Olives. A ritually pure kohen slaughtered the heifer and sprinkled its blood in the direction of the Temple seven times. The red heifer was then burned on a pyre, together with crimson dyed wool, hyssop, and cedar wood. In recent years, the site of the burning of the red heifer on the Mount of Olives has been tentatively located by archaeologist Yonatan Adler.
The existence of a red heifer that conforms with all of the rigid requirements imposed by halakha is a biological anomaly. The animal must be entirely of one color, and there is a series of tests listed by the rabbis to ensure this; for instance, the hair of the cow must be absolutely straight (to ensure that the cow had not previously been yoked, as this is a disqualifier). According to Jewish tradition, only nine red heifers were actually slaughtered in the period extending from Moses to the destruction of the Second Temple. Mishnah Parah recounts them, stating that Moses prepared the first, Ezra the second, Simon the Just and Yochanan the High Priest prepared two each, and Elioenai ben HaQayaph, Hanameel the Egyptian, and Yishmael ben Pi'avi prepared one each (Mishna Parah 3:5).
The extreme rarity of the animal, combined with the detailed ritual in which it is used, have given the red heifer special status in Jewish tradition. It is cited as the prime example of a ḥok, or biblical law for which there is no apparent logic. Because the state of ritual purity obtained through the ashes of a red heifer is a necessary prerequisite for participating in Temple service, efforts have been made in modern times by Jews wishing for biblical ritual purity (see tumah and taharah) and in anticipation of the building of the Third Temple to locate a red heifer and recreate the ritual. However, multiple candidates have been disqualified.
The Temple Institute, an organization dedicated to preparing the reconstruction of a Third Temple in Jerusalem, has been attempting to identify red heifer candidates consistent with the requirements of Numbers 19:1–22 and Mishnah Tractate Parah. In recent years, the institute thought to have identified two candidates, one in 1997 and another in 2002. The Temple Institute had initially declared both kosher but later found each to be unsuitable. The Institute has been raising funds in order to use modern technology to produce a red heifer that is genetically based on the Red Angus.. In September 2018, the institute announced a red heifer candidate was born saying "the heifer is currently a viable candidate and will be examined [to see] whether it possess[es] the necessary qualifications for the red heifer."
The non-canonical Epistle of Barnabas (8:1) explicitly equates the red heifer with Jesus. In the New Testament, the phrases "without the gate" (Hebrews 13:12) and "without the camp" (Numbers 19:3, Hebrews 13:13) have been taken to be not only an identification of Jesus with the red heifer, but an indication as to the location of the crucifixion.
Some Fundamentalist Christians believe that the Second Coming of Jesus Christ cannot occur until the Third Temple is constructed in Jerusalem, which requires the appearance of a red heifer born in Israel. Clyde Lott, a cattle breeder, is attempting to systematically breed red heifers and export them to Israel to establish a breeding line of red heifers in Israel in the hope that this will bring about the construction of the Third Temple and ultimately the Second Coming of Jesus.
The red heifer was also considered sacred to the Greek god Apollo. They are featured in many myths, including that of the creation of the lyre. In it Hermes steals Apollo's red heifers and then hides them. To escape Apollo's rage, Hermes creates the lyre.