At the end of the menstrual cycle (on condition, as stated, that the minimum days have passed), the woman must examine herself to make sure that the bleeding has stopped completely. This initial examination [bedika], which is called the hefsek tahara, must be performed toward evening, before sunset.

A woman performs the hefsek tahara by means of a small white cloth, whose cleanness is checked in advance. It is known as a bedika cloth, or in Hebrew, an ed bedika, literally “an examination witness,” because the examination serves as a reliable “witness” to the woman’s status. Pre-made packets of these cloths can be obtained in ritual baths, and in Israel they are often available in pharmacies and supermarkets.

Before doing the hefsek tahara, the woman must wash herself well, so that no traces of blood are left on her body which might then appear on the bedika cloth and incorrectly prevent her from being purified. Afterward, she should take a bedika cloth, examine it on both sides to ensure that it is entirely clean, wrap it around her finger, and then insert the wrapped finger into the vagina and rotate it gently but thoroughly. This test enables her to affirm that the bleeding has stopped completely and that the area is entirely clean of blood. If she finds faint blood marks on the bedika cloth, these might be residues of an old blood flow and it is recommended for her to examine herself again a few minutes later with another bedika cloth. She may repeat the action yet again if it seems that there is a reasonable chance of achieving a clean bedika. If the other bedika cloths are also stained and in the meantime the sun has set, she has no choice but to postpone the implementation of the hefsek tahara to the following day.

An important factor in maintaining the laws of family purity is knowing to approach a rabbi when necessary. The bedika cloths will often have stains, and in order to make a decision as to whether this is indeed blood or possibly some other secretion that does not confer ritual impurity, one requires halakhic knowledge and expertise. Consultation with a rabbi can save much confusion and aggravation.

It is highly recommended for each couple to choose a qualified rabbi to whom they can refer all problems in this field. Under no circumstances should the questions be considered unpleasant or embarrassing. The correct and healthy attitude toward this topic is the same as all mitzvot of the Torah. The rabbis involved in this practice are accustomed to such questions and they accept them respectfully and with patience.

From the day after performing the hefsek tahara, the woman begins counting seven “clean days,” on which she does not experience any bleeding. On each and every one of these days, she must examine herself in the same manner as for the hefsek tahara, with several differences. According to some opinions, she should not wash herself just before performing the examination. In addition, these examinations should be performed only once; she may not keep repeating them until the bedika cloth comes out clean. She performs the examination twice each day, immediately after arising in the morning, and before sunset in the evening.

Sometimes the count of “seven clean days” can be interrupted by the appearance of blood on a bedika cloth or a stain on an undergarment. In such cases, it is advisable to consult a rabbi and to follow his instructions. If a woman decides alone in cases of uncertainty, she might mistakenly be too lenient, but she might also be needlessly stringent. Both alternatives are problematic. If it is indeed blood, the woman will need to start the count of seven clean days over again.

In the night that follows these seven clean days, the woman immerses herself in a mikva.

In preparation for immersing in the mikva, the woman must thoroughly cleanse herself in a way that ensures that there is no dirt or anything else on her body that might interpose between her body and the water of the mikva.

Before immersing in the mikva, the woman should take a shower and wash her body well, especially in places that are hard to reach, such as inside the ears and in folds of the body. She must remove any makeup from her face. She must also untie any braids, remove any foreign object (beads, rubber bands, etc.) from her hair, and wash and comb through all the hair of her head. Likewise, she must clean her nails and remove any polish or coating from them. It is also mandatory for her to brush her teeth, even though the mikva water does not enter the mouth. The immersion must be performed without any jewelry on the body (including earrings, bracelets, rings, and the like).

Immersion in the mikva is not like bathing, as it includes a spiritual dimension of purification and renewal. For this reason, it is important to pause for a moment before immersing, to relax and leave behind the daily stresses of life. The woman should perform the necessary actions calmly, while preparing herself for the reunion she will have with her husband in the evening.

Present at the ritual immersion in the mikva is a designated female attendant, called a balanit in Hebrew, meaning literally “female bathhouse attendant.” This title is somewhat misleading, as her role is not limited to the technical operation of the mikva; rather, she serves as an instructor and guide in the purification process, while helping to ensure that the immersion is performed properly and without complication. It is important to be attentive to the instructions of the balanit, keeping in mind that there are often certain differences in prevailing customs between one mikva and another.

The immersion in the mikva is accompanied by a blessing:

“Blessed are You, Lord our God, King of the universe, who sanctified us through His commandments, and commanded us concerning immersion.”

The blessing should be recited after entering the waters of the mikva, when the entire body, apart from the head, is covered with water. The common Ashkenazic practice is to immerse once, then recite the blessing, and then to immerse again.

There are two dates in the year when immersion is forbidden and must be postponed for the following night: the night of Yom Kippur and the night of Tisha BeAv. The reason is that on these days it is prohibited to wash oneself, and it is also forbidden to engage in marital relations.

If the time for the immersion is a Friday night, all prior preparations must be performed before Shabbat, and the woman should arrive at the mikva at the start of Shabbat. The exact time for the immersion will be determined by the balanit.

When the night of immersion falls on a Saturday night, the woman should take a shower on Friday in preparation for the immersion, and then again on Saturday night, at which point she should perform the rest of the preparations for the immersion: washing the hair, cleaning her nails, brushing her teeth, etc.