Mezuzah

A mezuzah (Hebrew: doorpost) are religious texts (often contained in a decorative case) from Deuteronomy inscribed on parchment and rolled up in a case that is attached to the doorframe of many Jewish households in accordance with Jewish law. It is inscribed with specified Hebrew verses from the Torah. These verses comprise the Jewish prayer "Shema Yisrael", beginning with the phrase: "Listen, Israel, the Lord is our God, the Lord is One."

The mezuzah is not, as some suppose, a good-luck charm, nor does it have any connection with the lamb's blood placed on the doorposts in Egypt. Rather, it is a constant reminder of G-d's presence and G-d's mitzvot.
The scroll must be handwritten in a special style of writing and must be placed in the case to fulfill the mitzvah.