Menachot 35

The primary purpose and content of tefillin is given quite explicitly in the Torah: In four different passages, the Torah tells us to bind these words as a sign on our hands and as a symbol or band between our eyes, so that we remember God’s commandments and that God redeemed us from Egypt (Exodus 13:9, Exodus 13:16, Deuteronomy 6:8 and Deuteronomy 11:18.)  While there are a number of plausible interpretations of these verses (including through more metaphorical lenses), Jewish tradition understands them to mean that these four passages should be physically bound to one’s hand/arm and head in some fashion.
 
Given this basic task, the rabbis are left to fill in a huge number of details: What kind of containers will store these pieces of text? What should they be made of? How should they be decorated? In what manner should they be bound to the head and arm? Today’s daf answers many of these questions, usually deferring not to textual interpretation, but to received tradition.

Rav says: The base of the tefillin (upon which the boxes rest) is a halakhah given to Moses at Sinai.

Abaye says: The passageway (through which the straps are inserted) is a halakhah given to Moses at Sinai.

Abaye says: The letter shin (stamped into the head tefillin) is a halakhah given to Moses at Sinai …

Rabbi Yitzhak says: The straps being black is a halakhah given to Moses at Sinai …

It was taught in a beraita: The square shape of tefillin is a halakhah given to Moses at Sinai …

It was taught in the name of Rav: The shape of the knot of tefillin straps is a halakhah given to Moses at Sinai.

The concept of “a halakhah given to Moses at Sinai” is invoked throughout the Talmud to give justification to laws that don’t have an explicit source in the Torah or elsewhere in rabbinic literature. The authority of these laws does not rest in being derived from other sources, but rather from being passed down through the generations as received tradition. Later rabbis debate the exact meaning of this term. A literal understanding might be that God gave this exact verbal instruction to Moses on Mount Sinai but didn’t include it in the written Torah. A less literal interpretation is that the term communicates that a law is faithful to the written Torah and has a long pedigree, even if not included explicitly in all its details at revelation. In all cases, though, the message is that this is a tradition that we learned from our teachers, who learned it from their teachers, going back as far as we can remember. 

The numerous anecdotes on today’s daf also demonstrate this sense of tefillin as mimetic, interpersonal tradition. When discussing the position of the straps, the Gemara describes the rabbis’ different styles of wearing them:

Rabba would tie the straps and release them and let them fall behind him.

Rav Aha bar Ya’akov would tie them and braid them together.
Mar, son of Rabbana, would act like we do (and let the straps hang over the front of his body).

Rather than stating prescriptive laws in isolation, the rabbis seem to learn many of the details of tefillin by simply observing what their teachers and colleagues do. In several stories, the rabbis correct each other’s tefillin placement in real time. At one point, Rav Acha son of Rav Yosef asks whether one can stitch a torn tefillin strap back together, and Rav Ashi’s answer is that they should go and observe what other Jews seem to do. The Gemara paints a picture of tefillin as something whose essence is deeply rooted in the Torah, but whose details are learned primarily from other people, not from texts.
 
In fact, one of the last stories in this section asserts that this chain of personal tradition originated with none other than God and God’s own tefillin:

“And I will remove My hand, and you will see My back.” (Exodus 33:23) Rav Hana bar Bizna says that Rabbi Shimon Hasida says: This teaches that the Holy One, Blessed be He, showed Moses the knot of his tefillin.

The rabbis imagine that Moses, the very first person to learn about tefillin, did not learn from written or even verbal instructions alone — he too learned by watching his teacher. 

xRead all of Menachot 35 on Sefaria.

This piece originally appeared in a My Jewish Learning Daf Yomi email newsletter sent on February 15, 2026. If you are interested in receiving the newsletter, sign up here.