Mezuzah

A mezuzah ( "doorpost"; plural: mezuzot) is a piece of parchment called a klaf contained in a decorative case and inscribed with specific Hebrew verses from the Torah ( and ). These verses consist of the Jewish prayer "Shema Yisrael", beginning with the phrase: "Hear, O Israel, the (is) our God, the is One". In mainstream Rabbinic Judaism, a "mezuzah" is affixed to the doorpost of Jewish homes to fulfill the mitzvah (Biblical commandment) to "write the words of God on the gates and doorposts of your house" (). Some interpret Jewish law to require a "mezuzah" in every doorway in the home except bathrooms (which are not a living space), laundry rooms and closets, if they are too small to qualify as rooms. The klaf parchment is prepared by a qualified scribe (""sofer stam") who has undergone training, both in studying the relevant religious laws, and in the more practical parts i.e. carving the quill and practising writing. The verses are written in black indelible ink with a special quill pen made either from a feather or, in what are now rare cases, a reed. The parchment is then rolled up and placed inside the case.
Etymology.
In the Bible, the word "mezuzah" only refers to the two 'doorposts' or 'doorjambs' of a door, the upright posts on either side of it which support the lintel, and appears in various contexts unrelated to any religious commandment or parchment. The word later acquired the modern meaning of piece of parchment in post-Biblical Hebrew due to the Deuteronomy commandment above requiring to write verses on doorposts.
The word's origin is disputed:
Affixing the mezuzah.
According to "halakha", the "mezuzah" should be placed on the right side of the door or doorpost, in the upper third of the doorpost (i.e., approximately shoulder height), within approximately of the doorway opening. Care should be taken to not tear or damage the parchment or the wording on it, as this will invalidate the "mezuzah", which is considered Torah. Generally, "halakha" requires Jews living in the Diaspora (i.e., outside of the Land of Israel) to affix a "mezuzah" within 30 days of moving into a rented house or apartment. For a purchased home or apartment in the Diaspora, or a residence in Israel (owned or rented), the mezuzah is affixed immediately upon moving in. The reason for this difference is that there is an assumption that when a Jew lives in Israel, Israel shall remain his/her permanent residence, whereas a home in the diaspora is temporary. 
Where the doorway is wide enough, many Ashkenazi Jews tilt the mezuzah so that the top slants toward the room into which the door opens. This is done to accommodate the variant opinions of Rashi and of his grandson, Rabbeinu Tam, as to whether it should be placed vertically (Rashi) or horizontally (Rabbeinu Tam), and also to imply that God and the Torah (which the mezuzah symbolizes) are entering the room. The compromise solution was suggested by Rabbi Jacob ben Asher.
Most Sephardic, Mizrahi and other non-Ashkenazi Jews affix the mezuzah vertically, though Spanish and Portuguese Jews living in countries where the majority of Jews are Ashkenazim usually place it slanting.
The procedure is to hold the "mezuzah" against the spot upon which it will be affixed, then recite a blessing:
Any Jew can recite the blessing, provided they are old enough to understand the significance of the "mitzvah". After the blessing, the "mezuzah" is attached.
Whenever passing through the doorway, many people touch a finger to the mezuzah as a way of showing respect to God. Many people also kiss their finger after touching it to the mezuzah.
When affixing several "mezuzot", it is sufficient to recite the blessing once, before affixing the first one.
Checking the parchment.
Many observant Jews from all Jewish denominations have a qualified scribe check the mezuzot parchments for defects (such as small tears or faded lettering) at least twice every seven years. This job can be done by a sofer (scribe) or by anyone with similar training. A sofer also can make new mezuzot parchments which are in accordance with Jewish law.
Mezuzah cases.
The commandment to affix a mezuzah is widely followed in the Jewish world, even by Jews who are not religiously observant. While the important part of the mezuzah is the "klaf", or the parchment, and not the case itself, designing and producing mezuzah cases has been elevated to an art form over the ages. Mezuzah cases are produced from a wide variety of materials, from silver and precious metals, to wood, stone, ceramics, pewter, and even polymer clay. Some dealers of mezuzah cases will provide or offer for sale a copy of the text that has been photocopied onto paper; this is not a kosher (valid) mezuzah, which must be handwritten onto a piece of parchment by a qualified scribe.
Additional inscriptions.
It is very customary to write two inscriptions on the back of the parchment:
"Shaddai", ["Almighty"] one of the biblical names of God, also serves here as an acronym for "Shomer Daltot Yisrael", "Guardian of Israel's doors". Many mezuzah cases are also marked with the Hebrew letter (Shin), for "Shaddai".
"" is a Caesar cipher—a one-letter shift—of the third, fourth, and fifth words of the Shema, "Adonai, Eloheinu, Adonai", "The Lord, our God, the Lord"; it is written on the back of the case, opposite the corresponding words on the front. This inscription dates from the 11th century and is found among the "Hasidei Ashkenaz" (medieval German Jewish mystics).
The Sephardic custom (minhag) leaves out the phrase , and only the Hebrew word ("Shaddai") is written on the back of the mezuzah. This follows the Shulchan Aruch and the writings of the Rambam. The Ashkenazi custom of writing both phrases, however, was supported in the writings of the Remo. (Yoreh De'ah 288:15)
In this regard it is worthwhile to refer to the often cited passage from Rambam's "Mishneh Torah" which states:"It is a common custom to write [God's name,] Shaddai, on the outside of a mezuzah opposite the empty space left between the two passages. There is no difficulty in this, since [the addition is made] outside. Those, however, who write the names of angels, other sacred names, verses, or forms, on the inside [of a mezuzah] are among those who do not have a portion in the world to come. Not only do these fools nullify the mitzvah, but furthermore, they make from a great mitzvah [which reflects] the unity of the name of the Holy One, blessed be He, the love of Him, and the service of Him, a talisman for their own benefit. They, in their foolish conception, think that this will help them regarding the vanities of the world."
Amuletic usage of mezuzah.
The culture-comparative analysis suggests that the objects placed on domestic thresholds often bear the function of an amulet repelling the broadly understood evil. In fact, the early Rabbinic sources explicitly witness the belief in the anti-demonic function of mezuzot. This is the case in e.g. JT Megillah 4:12; BT Bava Metziya 102a; BT Pesahim 113b. The further analysis of the biblical and rabbinic texts ("inter alia" Deuteronomy 6, 11, Exodus 12, Mekhilta de-rabbi Ishmael 7,12 and BT Menahot 33b, 43b) shows that mezuzah is construed as a device protecting against the divine anger.
The belief in the protective power of mezuzah is prevalent in the modern times as well. In the 1970s after a series of terrorist attacks in Ma'alot, the representatives of Chabad-Lubavitch started the campaign for the systematic checking of mezuzahs. The general assumption underlying the action was that adhering to the "mitzvot" would guarantee personal safety.
Finally, according to various pieces of sociological research, approximately three-quarters of adults in Israel believe that the mezuzah literally guards their houses.
Karaite and Samaritan mezuzah.
This article deals mainly with the "mezuzah" as it is used in Rabbinic Judaism, but Karaite Judaism and Samaritanism have their own traditions.
In Karaite Judaism the deuteronomic verse "And you shall write them on the doorposts of your houses and your gates" () is interpreted to be a metaphor and not as referring to the Rabbanite "mezuzah". Thus Karaites do not traditionally use "mezuzot", but put up a little plaque in the shape of the two Tablets of the Law with the Ten Commandments. In Israel, where they might try not to make other Jews feel uncomfortable, many Karaites make an exception and place a mezuzah on their doorpost as well. The Karaite version of the "mezuzah" is fixed to the doorways of public buildings and sometimes to private buildings, too.
The Samaritans interpret the deuteronomic commandment to mean displaying any select text from the Samaritan version of the five Books of Moses. This can contain a blessing or a particularly holy or uplifting message. In the past they placed a stone plaque inscribed with the Ten Commandments above the house door, some examples dating back to the Byzantine (4th–7th century) and Early Muslim (7th–11th century) periods being now shown in the Israel Museum in Jerusalem. Nowadays a Samaritan "mezuzah" is usually made of either marble, a wooden plate, or a sheet of parchment or high quality paper, on which they inscribe select verses from the Samaritan Torah. This they place either above the house door, or inside the house, in the entrance hall or at a prominent place on a large wall. These "mezuzot" are found in every Samaritan household as well as in the synagogue. Today some Samaritans would also use a Jewish-style mezuzah case and place inside it a small written Samaritan scroll, i.e. a text from the Samaritan Torah, written in the Samaritan alphabet. The more such "mezuzot" there are in the house, the better it is considered to be.
Legal battles in the U.S..
The Jewish practice of affixing a mezuzah to the entranceway of a residential unit was rarely challenged in the United States or Canada, However, in Chicago in 2001, a condominium association at Shoreline Towers banned "mats, boots, shoes, carts or objects of any sort… outside unit entrance doors", which by board vote in 2004 was interpreted to be absolute. Shoreline Towers management removed the hallway mezuzot of condominium tenants. Complaints were subsequently filed with the Chicago Commission on Human Relations, Illinois Attorney General, and U.S. Department of Housing and Urban Development, alleging housing discrimination on the basis of religion Shoreline Towers was not the sole condominium association in Chicago with such a restriction, although one of them agreed to modify its rule.
On reading a news report of the mezuzah dispute, Chicago alderman Burton Natarus, drafted an amendment to the city's municipal code which made it illegal for a renter or owner of an apartment, house, or condo to be prohibited from "placing or affixing a religious sign, symbol or relic on the door, door post or entrance." Although there was opposition, it became law in Chicago that December. The first such legislation in North America, it included a maximum $500 fine for its violation.
Notwithstanding this legislation, in 2006, a federal court judge determined that the rule did not violate the Federal Fair Housing Act; the district court upheld the opinion on appeal in 2008; in 2009, the U.S. Court of Appeals for the 7th Circuit in Chicago reversed the 2008 decision, and the case proceeded. Meanwhile, records of the "Chicago Jewish Star" were unsuccessfully subpoenaed, and Illinois’ anti-SLAPP legislation was applied. In 2011, a confidential settlement to the Shoreline Towers disputes was achieved.
In 2006, a more narrowly focused amendment to the state's Condominium Property Act was initiated by Illinois Senator Ira Silverstein, the first such state law.
In 2006, a woman in a condo building in Fort Lauderdale, Florida was instructed to remove the mezuzah from her hallway unit and threatened with a fine. After a lengthy legal battle, the condo association was found guilty of discrimination. In 2008, House Bill 995, an amendment to the Florida Condominium Act modeled on the Illinois state legislation, became law.
In Texas in 2007 a couple living in Houston was instructed to "remove the item attached to your door frame" to avoid violating association rules. A legal battle ensued, during which a U.S. District Court judge ruled in 2008 on behalf of the condo association. Subsequently, the couple turned to Texas House of Representatives member Garnet F. Coleman. His bill to protect such religious displays, as introduced in 2009, was not adopted, but in June 2011 a slightly revised version (HB1278) was signed into law by Texas Governor Rick Perry.
A bill designed to prevent mezuzah bans nationwide was proposed in 2008 (H.R. 6932) by U.S. Congressman Jerrold Nadler. It never became law.