The word Mezuzah is derived from the Hebrew word for doorpost (Mezuzot), The Mezuzah is commonly thought to be the object that contains a small piece of parchment (klaf) which comes from a kosher species of animal on which is inscribed the verses of the "Shema and Vehahavta" (Devarim/Deuteronomy 6:4-9 and Devarim/Deut 11:13-21). However, the parchment is written by a sofer (scribe) in the same manner and script as the Torah and is actually the Mezuzah. Once the mezuzah has been written, it is rolled from left to right with the letters שדי and is placed in a protective case called a Mezuzot with the first letter of the Name (the letter Shin) visible or, more commonly, the letter Shin is written on the outside of the case.

Mezuzot are traditionally affixed to the doorpost of each room in the home and place of business, except for the bathrooms. The Torah only requires it to be affixed to the gates and doorposts of a house most commonly thought to be all outside doors.

Contrary to kabbalistic teachings the mezuzah is not a good-luck charm. They derive the explanation from the writing on the back of the parchment containing the word Shaddai which means "Almighty” to the acronym standing for shomer delatot yisrael: guardian of the doors of Israel thus acquiring the character of an amulet using the teaching of Rashi to support this: "[The mitzva of] mezuza is an obligation of the resident, for it is HIS GUARDIANSHIP" (Pesachim 4). His Guardianship would mean His position and responsibility of a guardian.

 If you place the parchment in the mezuzah case yourself, roll it from left to right so that the word Shaddai faces out. If your mezuzah has an opening, Shaddai should appear in it, otherwise align the word with the front of the case.

Why mount a Mezuzah?

In the Torah Shemot/Ex 12:49 it starts by letting us know that there is one law for the natural born and the stranger that sojourns with Israel. So when God commands the Jewish people to place a mark on their doorposts (mezuzot), (Devarim/Deuteronomy 6:9) to write them on the doorposts of your house it is a command directly from God to his people and all those that Sojourn or are grafted into the commonwealth of Israel (Eph 2:11-13).

Rabbinical Judaism considers the Mezuzot a reminder for us of God’s presence and of our duty to fulfill God’s commandments by having a house dedicated to his service. The Messianic perspective shows that the house is set apart to the service of God.

Where do you affix a Mezuzah?

The mezuzah is placed in on the right doorpost as one enters the room at the bottom of the upper third of the doorpost (shoulder height) in a slightly slanted position so that the top points toward the inside of the room.

Why is the case and scroll nailed or affixed to the right side doorpost on an angle? The Talmud in Menachot 33a it explains the differences between Rabbenu Tam and Rabbi Shlomo Ben Yitzckaki (Rashi). One stating that it should not be horizontal as a “nagar” sideways bolt and the other stating that a “nagar” is a vertical bolt. The Shulchan Aruch (set table – codification of the 16^th century)  and the Vilna Gaon agreed with Rashi’s understanding that a “negar” (Bolt) is horizontal and therefore a mezuzot should be mounted vertically. However Rabbi Moses Isserlis (the ReMa) the writer of the 16^th century halakha book HaMapah (the tablecloth) agreed with Rabbi Tam. He then made the decision that the mezuzot should be mounted on a slant toward the inside since it neither horizontal nor vertical.

Tradition has it that every time you pass through a door with a mezuzah on it, you touch the mezuzah and then kiss the fingers that touched it, expressing your love and respect for God.

What is the Blessing for Affixing a Mezuzah?

The ceremony for affixing the Mezuzot is called Chanukkat Ha-Bayit (dedication of the house). A brief blessing is recited.

Traditionally the blessing is only recited once (usually on the front door) for all the mezuzot in the house. After reciting the blessing generally no words are spoken until all mezozot are hung throughout the house.

Before affixing a mezuzah to a doorpost, the following blessing is recited:

ברוך אתה י-י א-להינו מלך העולם

אשר קרשנו במצותיו וצונן לקבוע מזוזה

Barukh ata Adonai Eloheinu Melekh ha-olam, asher kidshanu b’mitzvotav v’tzivanu likbo-a mezuzah.

Blessed are You, Adonai our God, Ruler of the universe, Who sanctifies us with holy commandments and commands us to fix a mezuzah.