The Mezzuzah is the container, which holds a hand written portion of the bible. A scribe has to learn several years to have the experience to write according to rabbinal kosher

In the Torah (Devarim- Deuteronomy 6:9), every Jew is commanded, "Write them on the doorposts of your house and on your gates." This commandment means that we must install a mezuzah on every doorpost in our home (whether we own or rent). A mezuzah has a very special parchment that has hand written on it the first two paragraphs of Kriat Shema, Devarim (Deuteronomy) 6:4-9 and 11:13-21.

The parchment, known in Hebrew as Klaf, is prepared from the skin of a kosher animal. A specially trained scribe, known as a Sofer, carefully writes the words using special black ink and a quill pen.

The letters must be written in the manner indicated by halacha (Jewish Law), and every letter and word must be correct.

Any mistakes or missing letters invalidates the entire parchment. It is very important to remember that a photocopied scroll, or a scroll written by someone who is not a qualified scribe, is invalid and doesn't fulfill the commandment. The parchment is then rolled so that letters are facing the inside.