And he would make a space above and a space below the text and would prepare the passages of the mezuza in the open manner, i.e., he would begin the second passage on the line following the end of the first passage. I said to him: My teacher, for what reason do you prepare the passages in the open manner, when in a Torah scroll those same passages are written in the closed manner? He said to me: Since the passages are not adjacent to one another in the Torah, as the first passage is Deuteronomy 6:4–9 and the second is Deuteronomy 11:13–21, I prepare them as open passages.

The Gemara continues: And Rav Ḥananel says that Rav says: The halakha is in accordance with the opinion of Rabbi Shimon ben Elazar. What, is it not correct that Rav stated this with regard to Rabbi Shimon ben Elazar’s opinion that one prepares the passages in the open manner? This would present a difficulty to the opinion of Rav Huna, Rav’s student, who wrote them in the closed manner.

The Gemara answers: No; he meant that the halakha is in accordance with the opinion of Rabbi Shimon ben Elazar with regard to the space that one must leave above and below the text. The Gemara asks: And how much space must one leave? Rav Menashya bar Ya’akov says, and some say it is Rav Shmuel bar Ya’akov who says: The space of a full scribe’s clip [atba], with which the sheets of parchment are held.

Abaye said to Rav Yosef: And you, do you not hold that when Rav said that the halakha is in accordance with the opinion of Rabbi Shimon ben Elazar he was referring to the space, not the manner of writing the passages? But Rav is of the opinion that an established custom must be observed, and nowadays the general custom is to write the passages of the mezuza in the closed manner.

The Gemara provides the source that according to Rav one must observe established customs. Ḥalitza is the ritual that frees the widow of a childless man from the obligation to enter into levirate marriage with her late husband’s brother. This ceremony involves the widow removing her brother-in-law’s sandal from his foot. Rabba spoke of the importance of observing customs in that context, as Rabba says that Rav Kahana says that Rav says: If Elijah comes and says that one performs ḥalitza with a shoe, the Sages listen to him. But if he says that one may not perform ḥalitza with a sandal, they do not listen to him, as the people are already accustomed to performing ḥalitza with a sandal.

The Gemara presents another version of Rav’s statement: And Rav Yosef says that Rav Kahana says that Rav says: If Elijah comes and says that one may not perform ḥalitza with a shoe, the Sages listen to him; if he says that one may not perform ḥalitza with a sandal, they do not listen to him, as the people are already accustomed to performing ḥalitza with a sandal.

Abaye continues: And we say, when discussing these versions of his statement: What is the difference between these two versions of his statement? The difference is whether one may use a shoe ab initio. In any case, according to both statements Rav maintains that a custom must be observed, and the custom in this case is to write the passages in a closed manner. Rather, must one not conclude from it that when Rav says that the halakha is in accordance with the opinion of Rabbi Shimon ben Elazar he was speaking of the space, not the manner of preparing the passages? The Gemara affirms: Conclude from it that this is correct.

§ Rav Naḥman bar Yitzḥak said: It is a mitzva ab initio to prepare the passages of a mezuza in the closed manner,but if one prepared them in the open manner, it is permitted to use the mezuza. And what is Rabbi Shimon ben Elazar saying when he says that Rabbi Meir would prepare the passages in the open manner? He means that one may prepare them even in the open manner.

The Gemara suggests: Let us say that a baraita supports his opinion: Similarly, just as one may not convert phylacteries of the head into phylacteries of the arm, with regard to a Torah scroll that became worn and parchment of phylacteries that became worn, one may not fashion them into a mezuza by excising the relevant passages, despite the fact that the Torah passages of a mezuza appear in them. This is prohibited because one does not reduce the sanctity of an item from a level of greater sanctity, that of a Torah scroll or phylacteries, to a level of lesser sanctity, that of a mezuza. The Gemara infers from this baraita: If it were permitted to reduce the sanctity of an item from a level of greater sanctity to a level of lesser sanctity, one could fashion a mezuza from a Torah scroll.

The Gemara explains the proof: But why is that the halakha, when here, in a Torah scroll, the passages are prepared in the closed manner, but there, in a mezuza, the passages are prepared in the open manner? Evidently, it is permitted to write a mezuza with the passages prepared in the closed manner. The Gemara refutes this proof: Perhaps one should infer from the baraita that were it not for the fact that it is prohibited to reduce the sanctity of an item from a level of greater sanctity to a level of lesser sanctity, one would be allowed to complete a line or two of a mezuza by sewing to it those lines from a Torah scroll or parchment of phylacteries that became worn, but one may not fashion an entire mezuza from a sheet of a Torah scroll or parchment of phylacteries, as the passages in a Torah scroll and phylacteries are prepared in the closed manner.

The Gemara asks another question: The baraita indicates that if it were permitted to reduce the sanctity of an item from a level of greater sanctity to a level of lesser sanctity, one could fashion a mezuza from phylacteries. But isn’t it taught in a baraita that it is a halakha transmitted to Moses from Sinai that the passages of phylacteries are written on parchment, the outer layer of an animal’s hide, and the passages of a mezuza are written on dokhsostos, the inner layer, and when writing on parchment, one writes on the side of the hide that faced the flesh; when writing on dokhsostos, one writes on the side of the hide on which there was hair? How, then, can one use the other side of the hide for a mezuza? The Gemara answers that this requirement is of dokhsostos for a mezuza is stated as a mitzva, but it is not indispensable.

The Gemara asks: But isn’t it taught in a baraita that if one changed between parchment and dokhsostos, the item is unfit? The Gemara responds that this baraita is referring to phylacteries that one wrote on dokhsostos in the manner of a mezuza, not to a mezuza which one wrote on parchment. The Gemara raises a further difficulty: But isn’t it taught in a baraita that if one changed whether in this manner or in that manner, it is unfit? The Gemara explains that this baraita does not mean that one changed either in the case of phylacteries or a mezuza. Rather, both this manner and that manner are referring to phylacteries, and this case is where one wrote them on parchment but on the side of the hide on which there was hair, not on the side that faced the flesh, and that