The Torah commands in Parashat Va’et’hanan (Debarim 6:9), “U’chtabtam Al Mezuzot Betecha U’bi’sh’arecha” – “And you shall write them on the doorposts of your home and upon your gates.” This command is repeated later, in Parashat Ekeb (Debarim 11:20), introducing an obligation to write these two sections of Biblical text upon parchment and affix the parchment to one’s doorpost. This Misva, of course, is known to us as the Misva of “Mezuza.” The two sections which must be affixed to the doorpost are the first two paragraphs of Shema (Debarim 6:4-9, 11:13-21). The reason for this Misva, the Sefer Ha’hinuch explains, is to provide a frequent reminder of our belief in Hashem and our obligations to Him. Each time we leave or enter the house, we see the Mezuza on the doorpost and are reminded of our subservience to the Almighty. Even a single missing letter, or improperly written letter, disqualifies the Mezuza. The Mezuza is to be placed on the right side when entering the home. The Gemara interprets the command of Mezuza as requiring placing the Mezuza “Derech Bi’atcha” – the way one enters the home, and thus, as one generally enters with the right foot first, the Mezuza should be placed on the right doorpost. All rooms in the house used for “Dira Shel Kabod,” respectable dwelling, require a Mezuza. This is to the exclusion of restrooms and bathing rooms, which do not require a Mezuza. The Torah requires placing Mezuzot “on the doorposts of your home,” and the Sages understood that this refers specifically to ordinary homes, as opposed to buildings endowed with halachic sanctity. Thus, Mezuzot are not required in the Bet Ha’mikdash, or in synagogues. Mezuzot should be checked twice every seven years to ensure they are kosher. Seven letters require special “crowns” in the scroll of the Mezuza – “Shin,” “Ayin,” “Tet,” “Nun, “Zayin,” “Gimal” and “Sadi.” If a person rents a house outside the Land of Israel, then he must affix Mezuzot within thirty days of moving into the home. In the Land of Israel, however, one is considered to establish permanent residence as soon as he moves into the home, and he must therefore affix Mezuzot immediately. One who rents a house bears the obligation to affix Mezuzot, and when he moves out of the residence, he must leave the Mezuzot behind, unless a non-Jew will be moving into the residence, in which case he should take the Mezuzot with him. Mezuzot are required on all doors in a home, though a number of conditions apply. First, a room requires a Mezuza only if its area is at least four square Amot, and it has doorposts and a lintel above them. Additionally, the room must be roofed. The Sefer Ha’hinuch, following the view of the Rambam, maintains that only doorways with a door require a Mezuza. The majority of Rishonim, however, disagree, and maintain that a Mezuza is required on a doorpost regardless of whether or not there is a door. The doorway must be at least ten Tefahim (handbreadths) high. As mentioned, only rooms used for “respectable” purposes require a Mezuza, as opposed to restrooms and bathing rooms, which do not. Buildings designated for animals – such as barns and stables – do not require Mezuzot. A Mezuza is required only in a permanent residence; a Sukka, which is a temporary, seven-day residence, does not require a Mezuza. This obligation applies in all places and in all times periods, and is binding upon both men and women. One who failed to affix a Mezuza to a doorway that requires a Mezuza has violated this command, and must immediately affix a Mezuza. It is noteworthy that in discussing the Misva of Mezuza, the Sefer Ha’hinuch makes no mention of the common notion of a Mezuza providing protection to the home. This omission is likely due to the fact that the Rambam, in Hilchot Mezuza (5:4), strongly condemns those who regard the Mezuza as a sort of amulet that magically brings protection. Interestingly, however, there is one passage in the Gemara which implies that one indeed earns p