The Gemara raises a difficulty: But Rav Ḥisda and Rabba bar Rav Huna would pray in the evening with phylacteries. The Gemara explains: That opinion represented in this incident disagrees with the ruling of Rav Naḥman.

The Gemara asks: And did Rabba bar Rav Huna actually say this, that the mitzva of phylacteries applies at night? But doesn’t Rabba bar Rav Huna say: If it is uncertain whether it is nightfall or whether it is not nightfall, one neither removes his phylacteries, as it is not yet definitely night, nor dons them ab initio. This indicates that if it is definitely nightfall, one removes his phylacteries. The Gemara answers: Rabba bar Rav Huna’s ruling there was stated with regard to Shabbat eve, as one may not don phylacteries on Shabbat, when the mitzva does not apply.

The Gemara raises a difficulty with regard to this answer: What does Rabba bar Rav Huna hold? If he holds that night is a time when one performs the mitzva of wearing phylacteries, then Shabbat is also a time when one performs the mitzva of wearing phylacteries. If he holds that Shabbat is not a time when one performs the mitzva of wearing phylacteries, then night is also not a time when one performs the mitzva of wearing phylacteries. The reason for this statement is that from the source where Shabbat is excluded from the mitzva of phylacteries, nights are excluded from there as well.

As it is taught in a baraita with regard to the end of the passage of the Torah that discusses both the mitzvot of the Paschal offering and phylacteries: “And you shall observe this ordinance in its season from year [miyamim] to year” (Exodus 13:10). This indicates that these mitzvot apply during the days [yamim] but not during the nights. Furthermore, the letter mem, meaning from, in the term: “From year [miyamim],” teaches: These mitzvot apply on some days, but not on all days. This excludes Shabbatot and Festivals, on which phylacteries are not worn. This is the statement of Rabbi Yosei HaGelili. Rabbi Akiva says: This verse, mentioning an ordinance, is stated only with regard to the Paschal offering, and it is not referring to phylacteries at all. Evidently, Rabbi Yosei HaGelili, who says that at night one is exempt from the obligation of donning phylacteries, says that on Shabbat one is exempt as well.

The Gemara answers: Rabba bar Rav Huna derives the exemption from the obligation to don phylacteries on Shabbat from a different source, the source where Rabbi Akiva derives it from, as it is taught in a baraita that Rabbi Akiva says: One might have thought that a person should don phylacteries on Shabbatot and Festivals. To counter this, the verse states: “And it shall be for a sign for you on your arm, and for a remembrance between your eyes, so that God’s law shall be in your mouth; for with a strong arm God brought you out of Egypt” (Exodus 13:9). This teaches that the obligation to don phylacteries applies when the Jewish people require a sign to assert their status as God’s nation, i.e., during the week. This serves to exclude Shabbatot and Festivals, as they themselves are signs of the Jewish people’s status as God’s nation and a remembrance of the exodus from Egypt. Consequently, no further sign is required on these days.

Rabbi Elazar says: Anyone who dons phylacteries after sunset violates a positive mitzva. And Rabbi Yoḥanan says: He violates a prohibition. The Gemara suggests: Let us say that these Sages disagree with regard to the principle that Rabbi Avin says that Rabbi Ile’a says. As Rabbi Avin says that Rabbi Ile’a says: Any place where it is stated in the Torah any of the terms: Observe, or: Lest, or: Do not, this means nothing other than a prohibition, as these are negative terms.

The Gemara explains this suggestion: As this Sage, Rabbi Yoḥanan, is of the opinion that the ruling is in accordance with the opinion of Rabbi Avin, and therefore the verse: “And you shall observe this ordinance in its season from year to year,” from which the exclusion of nights is derived, is a prohibition, as it employs the term “observe.” And that Sage, Rabbi Elazar, is of the opinion that the ruling is not in accordance with the opinion of Rabbi Avin, and therefore the term: “And you shall observe,” is a positive mitzva.

The Gemara counters: No, everyone is of the opinion that the ruling is in accordance with the opinion that Rabbi Avin says that Rabbi Ile’a says, and here they disagree with regard to this: One Sage, Rabbi Elazar, holds that the term “observe” written with regard to a prohibition has the status of a prohibition, whereas that same term “observe” written with regard to a positive mitzva has the status of a positive mitzva, as the Torah is issuing a warning to take special care in the observance of a mitzva. Accordingly, the command with regard to the positive mitzva of phylacteries is a positive mitzva. And one Sage, Rabbi Yoḥanan, holds that the term “observe” written with regard to a positive mitzva is also a prohibition.

And Rabbi Elazar says: And although it is prohibited to don phylacteries at night, if one does so in order to safeguard them from theft and the like, it is permitted.And Ravina said: I was sitting before Rav Ashi and it grew dark, and he donned phylacteries. And I said to him: Does the Master need to safeguard them? And he said to me: Yes. But I saw that his intention in donning them was not that he needed to safeguard them; rather, Rav Ashi holds: This is the halakha, that night is an appropriate time for phylacteries, but a public ruling is not issued to that effect.

Rabba bar Rav Huna says: A person is obligated to touch his phylacteries regularly for the entire time that he is wearing them. This is derived from an a fortiori inference from the frontplate of the High Priest, as follows: And if with regard to the frontplate, which has only one mention of God’s name, the Torah states: “And it should be always upon his forehead” (Exodus 28:38), which means that the High Priest must always be aware that the frontplate is placed on his head and that he should not be distracted from it, then with regard to phylacteries, which have numerous mentions of God’s name, all the more so one must always be aware of them.

§ The Sages taught with regard to the verse: “And it shall be for a sign for you on your arm [yadkha]” (Exodus 13:9), that this is referring to the left arm. Do you say it means the left arm, or is it only the right arm? The verse states: “Even My hand [yadi] has laid the foundation of the earth, and My right hand [vimini] has spread out the heavens” (Isaiah 48:13). And another verse states: “Her hand [yadah] she put to the tent pin, and her right hand [viminah] to the workmen’s hammer” (Judges 5:26), and another verse states: “Why do You withdraw Your hand [yadkha], even Your right hand [viminekha]? Draw it out of Your bosom and consume them” (Psalms 74:11). All these verses employ the term yad with regard to the left hand, and use the term yamin, literally, right, without the term yad, to indicate the right hand.