Handwashing in Judaism

and custom prescribe ritual hand washing in a number of situations. This practice is generally known by the Hebrew term , which means "taking up of the hands."
The Talmud used the requirement of handwashing in, "And whomsoever he that hath the issue toucheth, without having rinsed his hands in water, he shall wash his clothes, and bathe himself in water, and be unclean until the even", as a hint for general handwashing law, using the principle of asmakhta or "allusion."

Occasions for hand washing

Before eating bread

requires the hands to be washed before eating a meal containing bread, which involves pouring water over both hands up to the wrists. In some places, this act is repeated twice. This washing was initially known as mayim rishonim, he requires handwashing. However, the blessing over handwashing must be recited whenever eating at least 2.2 oz. of bread.
This only applies to bread made from one of the five chief grains. The washing is performed by pouring water from a cup over each hand, whether the hands were dirty or not. Most poskim require pouring water first over one's left hand, followed by pouring water over one's right hand. The water used to perform handwashing must be water that has not been used for other work, nor has the water's appearance changed in color. Each handwashing is followed by lifting-up of both hands and blessing over the handwashing, which is immediately followed thereafter by thoroughly drying the hands by wiping them with a towel. Drying off the hands is part and parcel with the ritual of washing.
The Gemarah of the Babylonian Talmud contains homiletic descriptions of the importance of the practice, including an argument that washing before meals is so important that neglecting it is equivalent to unchastity, and risks divine punishment in the form of sudden destruction or poverty.
Rabbinic law requires that travelers go as far as four biblical miles to obtain water for washing before eating bread if there is a known water source there. This applies only to when the water source lies in one's direction of travel. However, had he already passed the water source, he is only obligated to backtrack to a distance of one biblical mile. The one exception to this rule is when a man or a party of men are encamped while on a journey, and there is no water to be found in the vicinity of their camp, in which case the Sages of Israel have exempted them from washing their hands before breaking bread.

After eating bread (Mayim Acharonim)

Rabbinic sources discuss the practice of washing hands after a meal before reciting Birkat Hamazon. This practice is known as mayim acharonim. According to the Talmud, the washing is motivated by health concerns, to remove the "salt of Sodom" which may have been served at the meal - as salt originating from that region allegedly causes blindness should it be on one's fingers and they happen to touch their eyes. The Talmud considered mayim acharonim obligatory, and more important that washing before the meal. Many, but not all, later sources agree; for example: Shulchan Aruch, Orach Chaim 181:1.
However, Tosafot ruled that mayim acharonim is not required in current circumstances since the salt of Sodom is no longer served at meals. Similarly, Yaakov Emden ruled that it is not required since nowadays it is customary to eat with forks and knives and salt is unlikely to get on the fingers. Based on these sources, in many communities nowadays mayim acharonim is not practiced. Nevertheless, many others continue to practice it. One reason to continue practicing it is the principle that if the underlying reason behind a rabbinic ruling no longer applies, the ruling is not automatically canceled. Another reason has given the assertion that in every kor of salt, there is to be found a qurtov of salt of Sodom.
Although mayim acharonim was once not widely practiced, it has undergone something of a revival. It has become more widely observed in recent years, particularly for special meals such as the Shabbat and Jewish holidays.
No blessing is recited on this washing. Generally, only a small amount of water is poured over the outer two segments of the fingers, while a minority wash the entire hand up to the wrist. The water is sometimes poured from a special ritual dispenser. One should not pause between the washing and reciting birkat hamazon.

Thematic interpretations

explained that our involvement in the physical act of eating can potentially diminish our sense of holiness. To counteract this influence, we wash our hands after the meal. The Talmudic Sages spoke of washing away the "salt of Sodom" – a place whose very name symbolizes selfishness and indifference to others. "This dangerous salt, which can blind our eyes to the needs of others, is rendered harmless through the purifying ritual of mayim acharonim."

Before eating dipped fruit or vegetables

Some sources speak of washing hands before eating a piece of food dipped in a liquid which then clings to that piece. While the Shulhan Arukh requires the washing of hands before eating fruits that are merely damp with one of the seven liquids, Maimonides does not mention this stringency in his Mishneh Torah. Rabbi Yosef Qafih wrote that the enactment only applied to dipping fruits or vegetables in a liquid, but not when wetness merely clung to those fruits or vegetables by rinsing. Sephardic tradition is not to make a blessing over this handwashing, while Yemenite Jewish tradition is to make a blessing over this handwashing, since 'wherever there is a custom, the rule to be lenient in cases of doubtful blessings does not apply'.
Nowadays this washing is not widely practiced, with one notable exception: During a Passover Seder, the hands are washed without reciting a blessing before eating karpas, a washing referred to as "Urchatz."

Before worship

According to the Shulchan Aruch, a person should wash both hands before prayer. This hand washing does not require a cup, though many have the custom to use a cup. No blessing is recited on this washing. If water cannot be obtained, the hands may be cleaned differently.
As the Shacharit prayer is commonly recited shortly after awakening, many Jews rely on handwashing upon awakening and do not wash their hands again before Shacharit.
This washing is likened to the ritual purification required before entering the Temple in Jerusalem, in whose absence prayer, in Orthodox Judaism, serves in its place.

Before the Priestly Blessing

In Orthodox Judaism, Kohanim offer the Priestly Blessing before the congregation on certain occasions. Before performing their offices, they are required to wash their hands. Judaism traces this requirement to, which requires the priests to wash their hands before Temple service. The verse also refers to the washing of the feet, which is generally not practiced without a Temple in Jerusalem.
The water for this washing is commonly poured on the priests' hands by Levites, priests who assist Kohanim in other ways.
In some communities, priests do not wash their hands before the Priestly Blessing because they have already washed their hands upon awakening before the prayer.

After sleeping

According to the Shulchan Aruch, a person who has slept is required to wash upon arising, and says the netilat yadayim blessing. This ritual is known by the term, and in Hebrew as netilat yadayim shacharit. The Yiddish term is also used for a special cup for washing. The water is poured out from a vessel three times, intermittently, over each hand. Most poskim require pouring water first over one's right hand, followed by the left hand, which order differs from the handwashing done for eating bread, where it is customary to begin with one's left hand.
Reasons given for this washing vary: to remove an evil spirit from one's fingers, or in preparation for the morning prayer, or to make the hands physically clean before reciting blessings and studying Torah. This is performed when waking from a full night's sleep, or even after a lengthy nap.
The Talmud states God commanded Jews to wash their hands and provides the text of the netilat yadaim blessing still in use.

Other occasions

After touching part of the body which is dirty or customarily covered such as the private parts, back, arm pits, inside of nose or ear, the scalp, or the sweat from one's body, or one's shoes
Upon leaving a latrine, lavatory or bathhouse, as a symbol of both bodily cleanliness and of removing human impurity. Handwashing after excretion is sometimes referred to as "washing asher yatzar," referring to the blessing recited once the hands have been washed after excretion.
Upon leaving a cemetery
After cutting one's hair or nails
After a blood letting; while blood letting is no longer performed, some wash their hands after donating blood.
To remove corpse uncleanness after participating in a funeral procession or coming within four cubits of a corpse
Some have the custom of washing their hands before scribal work
Laws of washing

Blessing said before washing

A blessing is prescribed over handwashing before eating bread and when one wakes up from sleep in the morning. Maimonides prescribes saying the blessing before one actually pours water over his hands, as brought down by the Code of Jewish Law, and the Talmud requiring that for all of the commandments the recitation of the blessing must be made prior. For some, the custom has developed to recite the blessing only after he has poured water over his hands and rubbed them together while they are raised in the air to the height of their chin before drying them with a towel.
The blessing text is as follows: "Blessed are you, O Lord, our God, King of the Universe, who has sanctified us through your commandments and has commanded us concerning the washing of hands". Immediately following the recital of the blessing, one must dry the hands with a towel or similar.
A text from the Cairo Geniza, following the Palestinian minhag, has been discovered where the blessing concluded al mitzvat shetifat yadayim.