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 decontamination process (Numbers 19:19). The priests who have performed the ritual then become impure themselves. The priest who performs the ritual must then bathe himself and his clothes in water. He shall be deemed unclean until evening.
The Mishnah, the central compilation of Rabbinic Oral Law, contains a tractate on the Red Heifer, tractate Parah in Seder Taharot, 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 (Caesarian section renders a Heifer candidate invalid). The water must be "living" or spring water. This is a stronger requirement than for a mikvah. Rainwater accumulated in a cistern is permitted for a mikvah, 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 Spring of Shiloah. The ceremony involved was complex and detailed. To ensure complete ritual purity of those involved, enormous care was taken to ensure that no-one involved in the Red Heifer ceremony could have had any contact with the dead, 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:
According to the Mishnah, the ceremony of the burning of the Red Heifer itself took place on the Mount of Olives. A pure priest slaughtered the Heifer, and sprinkled of its blood in the direction of the Temple seven times. The Red Heifer was then burnt on a pyre, together with crimson dyed wool, hysop, 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 absolute rarity of the animal, combined with the mystical 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 chok, or biblical law for which there is no apparent logic, and is therefore of absolute Divine origin. Because the state of ritual purity obtained through the ashes of a Red Heifer is a necessary prerequisite for participating in any Temple service, efforts have been made in modern times by Jews wanting to rebuild the Temple to locate a red heifer and recreate the ritual. Most recently, a cow that was considered a potential candidate was disqualified because it sprouted several black hairs.
The non-canonical Epistle of Barnabas (7:4) explicitly equates the Red Heifer with Jesus. In the New Testament, the phrases "without the camp" and "without the gate" (Hebrews 13:12,13, KJV) 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. This is the thesis of Ernest L. Martin, in his book, Secrets of Golgotha, (1984).
The Quran mentions the story of the Cow in the chapter Al-Baqara (The Cow), in verses 2.67-2.73. The story becomes the name of this longest chapter of the Qur'an.
The Cow required at first was just a 'cow'. During the story, more restrictions were given, and the color of the cow is required to be yellow after Moses was asked to give details on the color of the cow.
The English interpretation by Pickthall is:
2.67 And when Moses said unto his people: Lo! Allah commandeth you that ye sacrifice a cow, they said: Dost thou make game of us ? He answered: Allah forbid that I should be among the foolish! 2.68 They said: Pray for us unto thy Lord that He make clear to us what (cow) she is. (Moses) answered: Lo! He saith, Verily she is a cow neither with calf nor immature; (she is) between the two conditions; so do that which ye are commanded. 2.69 They said: Pray for us unto thy Lord that He make clear to us of what colour she is. (Moses) answered: Lo! He saith: Verily she is a yellow cow. Bright is her colour, gladdening beholders. 2.70 They said: Pray for us unto thy Lord that He make clear to us what (cow) she is. Lo! cows are much alike to us; and Lo! if Allah wills, we may be led aright. 2.71 (Moses) answered: Lo! He saith: Verily she is a cow unyoked; she plougheth not the soil nor watereth the tilth; whole and without mark. They said: Now thou bringest the truth. So they sacrificed her, though almost they did not. 2.72 And (remember) when ye slew a man and disagreed concerning it and Allah brought forth that which ye were hiding. 2.73 And We said: Smite him with some of it. Thus Allah bringeth the dead to life and showeth you His portents so that ye may understand.
In his note to the above verses, Muhammad Asad (formerly Leopold Weiss), a Jewish convert who translated the Qur'an into English provides the following explanation:
"..their obstinate desire to obtain closer and closer definitions of the simple commandment revealed to them through Moses had made it almost impossible for them to fulfill it. In his commentary on this passage, Tabari quotes the following remark of Ibn Abbas:" If [in the first instance] they had sacrificed any cow chosen by themselves, they would have fulfilled their duty; but they made it complicated for themselves, and so God made it complicated to them." A similar view has been expressed, in the same context, by Zamakhshari. It would appear that the moral of this story points to an important problem of all (and, therefore, also of Islamic) religious jurisprudence; namely the inadvisability of trying to elicit additional details in respect of any religious law that had originally been given in general terms - for, the more numerous and multiform such details become, the more complicated and rigid becomes the law. The point has been acutely grasped by Rashid Rida, who says in his commentary on the above Qur'anic passage (see Manar I, 345f):" Its lesson is that one should not pursue one's [legal] inquiries in such a way as to make laws more complicated...This was how the early generations [of Muslims] visualized the problem.They did not make things complicated for themselves - and so, for them, the religious law [din] was natural, simple and liberal in its straightforwardness. But those who came later added to it [certain other] injunctions which had been deduced by means of their own reasoning [ijtihad]; and they multiplied those [additional] injunctions to such an extent that the religious law became a heavy burden on the community." For the sociological reason why the genuine ordinances of Islamic Law - that is, those which have been prima facie laid down as such in the Qur'an and the teachings of the Prophet - almost always devoid of details, I would refer the reader to my book State and Government in Islam (pp. 11 ff. and passim). The importance of this problem, illustrated in the above story of the cow - and correctly grasped by the Prophet's Companions - explains why this surah has been entitled "The Cow".
Muhammad Asad further refers to following Qur'anic verses to provide additional explanation:
"O you who have attained faith! Do not ask about matters which, if they were to made manifest to you [in terms of law], might cause you hardship; for, if you should ask about them while the Qur'an is being revealed, they might [indeed] be made manifest to you [as laws]. God has absolved [you from any obligation] in this respect: for God is much-forgiving, forbearing. People before your time have indeed asked such questions - and in result thereof have come to deny the truth." Qur'an 5:101-102.
Muhammad Asad provides the following notes to explain the above qur'anic verses:
"... An illustration of this problem has been provided in the following authentic Tradition, quoted by Muslim on the authority of Abu Hurayrah. In one of his sermons, the Prophet said:" O my people! God has ordained the pilgrimage (al-hajj) for you; therefore perform it." Thereupon somebody asked. "Every year, O Apostle of God?" The Prophet remained silent; and the man repeated his question twice. The Prophet said:"Had I answered 'yes', it would have become incumbent on you [to perform the pilgrimage every year]; and, indeed, it would have been beyond your ability to do so. Do not ask me about matters which I leave unspoken: for behold, there were people before you who went to their doom because they had put too many questions to their prophets and thereupon disagreed [about their teachings]. Therefore, if I command you anything, do of it as much as you are able to do: and if I forbid you anything, abstain from it."
Muhammad Asad further stated:"...by leaving certain matters unspoken, God has left them to man's discretion, thus enabling him to act in accordance with his conscience and the best interest of the community.... Rashid Rida thus explains the above verse:" Many of our jurists (fuqaha) have, by their subjective deductions, unduly widened the range of man's religious obligations (takalif), thus giving rise to the very difficulties and complications which the clear wording [of the Qur'an] had put an end to; and this has led to the abandonment, by many individual Muslims as well as by their governments, of Islamic Law in its entirety" (Manar VII. 138)."