Mikveh

A collection of water

A pool or bath of clear water, immersion in which renders ritually clean a person who become ritually unclean through contact with the dead (Num. 19) or any other defiling object or through an unclean flux from the body (Lev. 15) and especially a menstruant.

It is similarly used for vessels (Num 31: 22- 23). At the present day the chief use of the mikveh is for the menstruant. since the laws of ritual impurity no longer apply after the destruction of the Temple. However, since according to the halakhah the contracting of marital relations while the wife is in the state of niddah“Menstrous Woman” — According to Jewish law, a woman is forbidden to maintain sexual relations with her husband during and for sometimes both before and after her menses. is a particularly severe offense, punishable by karet, and according to one opinion in the Talmud (not however accepted as halakhah), that a child born of such a union is a mamzer, the rabbis insisted meticulous adherence to the laws of immersion in a mikveh before his mother could resume marital relations.

They are also obligatory for the immersion of proselytes, as part of the ceremony of conversion. In addition immersion in the mikveh is still practiced by various groups as an aid to spiritually, particularly on the eve of the Sabbath and festivals, especially the Day of Atonement (see Ablution) and the customs still obtains, in accordance with Numbers 31:22 – 23 to immerse new vessels and utensils purchased from non-Jews.

Mikveh
Teachings of Maimonides

It is emphasized that the purpose of immersion is not physical, but spiritual, cleanliness. Maimonides concludes his codification of the laws of the mikveh with the following statement:

It is plain that the laws about immersion as means of freeing oneself from uncleanness are decrees laid down by Scripture and not matters about which human understanding is capable of forming a judgment; for behold, they are included among the divine statues. Now ‘uncleanness is not mud or filth which water can remove, but is a matter of scriptural decree and dependent on the intention of the heart. So the Sages have said ‘If a man immerses himself without special intention, it is though he has never immersed himself at all’. However we may find some indication [for moral basis] of this: Just as one sets his heart on becoming clean as soon as he has immersed himself, although nothing new has befallen his body, so, too, one who sets his heart on cleansing himself from uncleanness that beset men’s souls – namely, wrongful thoughts and false convictions – becomes clean as soon as he consents in his heart to shun those counsels and brings his soul into the waters of pure reason. Behold, Scriptures say ‘And I will sprinkle clean water upon you and you shall be clean; from all your uncleanness and from your idols I will cleanse you [Ezek, 36:25] (Yad, mikva’ot 11:12).

Mikveh
Rabbinical Teachings

Stress on intention is passed from Judaism into Islam. “Purity is the half of faith” is the saying attributed to Muhammad himself and the general laws of uncleanness in Islam bear a striking resemblance to those of Judaism. (Encyclopedia of Islam, s.v.Takara)

According to biblical law any collection of water, drawn or otherwise, is suitable for a mikveh as long as it contains enough for a person to immerse himself (Yad, ibid. 4:1).
The rabbis, however, enacted that only water which had not been drawn, i.e., has not been in a vessel or receptacle, may be used; and they further established that the minimum quantity for immersion is that which is contained in a square cubit noun — an ancient measure of length, approximately equal to the length of a forearm. It was typically about 18 inches or 44 cm, though there was a long cubit of about 21 inches or 52 cm. — ORIGIN Middle English : from Latin cubitum ‘elbow, forearm, cubit’. For more info click here to the height of three cubits noun — an ancient measure of length, approximately equal to the length of a forearm. It was typically about 18 inches or 44 cm, though there was a long cubit of about 21 inches or 52 cm. — ORIGIN Middle English : from Latin cubitum ‘elbow, forearm, cubit’. For more info click here.

A mikveh containing less than this amount (which they estimated to be a volume of 40 seah, between 250 1,000 liters according to various calculations) becomes invalid should three log of water fall into it or be added. However, if the mikveh contains more than this amount it can never become invalid no matter how much drawn water is added to it.

For more info on weights and measures click here