Two portions of Deuteronomy are written on the Mezuzah parchment scroll in their original Hebrew. The Mezuzah scroll is made from handmade parchment from a kosher animal and inscribed in black ink with a special quill pen. It is written by a specially trained, devout scribe, known in Hebrew as a sofer. The sofer concentrates intensely and writes with special Hebrew characters in the writing style of Rabbi Isaac Luria.
A Mezuzah has 713 letters. Every letter has numerous laws pertaining to its form. In order for a Mezuzah to be written in accordance with all of the laws, it must meet thousands of requirements.
If even one of the Mezuzah’s 713 letters is missing, or shaped incorrectly, the Mezuzah is rendered invalid and the commandment is unfulfilled. Even the best scribe is human and subject to error. While some errors can be corrected in accordance with Jewish law, others cannot. Therefore, when a Mezuzah is purchased from a reputable seller, it is inspected by a second scribe before being sold.