A mezuzah [Hebrew: מְזוּזָה (mezuzah) meaning “doorpost”; plural: מְזוּזוֹת (mezuzot)] is a hand scribed parchment which contains two portions of Torah; Shema (Deuteronomy 6:4-9) and Vehavta (Deuteronomy 11:13-21). The Shema (Deuteronomy 6:4-9) begins with “Hear O Israel, the Lord is our God, the Lord is One.” and the Vehavta, include the verse: “And you shall inscribe these words upon the doorposts of your house and upon your gates.”
The parchment is stored in a protective case and hung on the doorposts of Jewish homes. The Mezuzah is not the decorative case but rather refers to the parchment inside. The decorative case is there to protect the parchment. Often, the parchment is further wrapped in plastic wrap if it is exposed to the elements, to protect it.
According to custom mezuzot should be placed on the right side of the door or doorpost when facing the door, in the upper third of the doorpost. Some Jews hang a mezuzah on every doorway in the home (except bathrooms) whereas others hang them on the doorposts of doors that have an entry from outside the home. This is what we do. Observant Jews will kiss their finger tip and then touch it to the mezuzah when entering the house as a way of showing respect to God and His Word.
The parchment (klaf) come from a kosher species of animal and is inscribed by hand. The sofer (Scribe) who writes the parchment has undergone many years of training and inscribes the mezuzah in the same manner and script as the Torah. The verses are written in black indelible ink with a special quill pen. When complete, the parchment is then rolled up from left to right with the word שדי (“Shaddai”) visible on the exposed edge) and placed inside the case. The Hebrew word שדי (Shaddai) is one of the Biblical names of God means “Almighty” and appears on the exposed part of the klaf as well as on the Mezuzah case itself (which may only have the first letter ש (“Shin”)). Shaddai also serves as an acronym for Shomer Daltot Yisrael which means “Guardian of Israel’s doors”.
The requirements in writing a Mezuzah parchment is the same as writing a Torah scroll; any mistake invalidates the entire parchment. Many observant Jews will have a qualified scribe check the mezuzot parchments for defects (such as small tears or faded lettering) at least twice every seven years. I check mine before hanging it on a new home, as I did last night (see photo).
While the important part of the mezuzah is the klaf or parchment, 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 a copy of the text that has been photocopied onto paper, however this is not considered a Kosher (valid) mezuzah. The klaf in our mezuzot are handscribed.
Ashkenazi Jews (Eastern European Jews) tilt the mezuzah so that the top slants toward the room into which the door opens, whereas most Sephardim (Middle Eastern Jews) Jews affix the mezuzah vertically. Jews living in countries where the majority of Jews are Ashkenazim usually place it slanting (which is what I do, although Sephardic).
Generally, mezuzot are hung immediately upon moving in or within 30 days of moving into a rented house or apartment in the Diaspora (outside the Land of Israel). The reason for this difference is that there is an assumption that when a Jew lives in Israel, Israel will remain their permanent residence, whereas a home in the Diaspora is temporary.
The mezuzah reminds us to keep God’s words constantly in our minds and in our hearts and to “teach them to your children when you walk by the way, when you lie down and when your rise up”. This is the main reason I hang mezuzot on my door posts (and also wear a decorative one around my neck).