Study Menachot folio 37A with parallel Hebrew-English text, traditional commentary, and modern study tools. Free access to Babylonian Talmud online.
R' Yosei HaḤorem says: This is no proof, as we have found that the right hand is also called yad, as it is stated: “And when Joseph saw that his father was laying his right hand [yad yemino]” (Genesis 48:17). The Talmud asks: And the other tanna, who maintains that the right hand is not called yad,
R' Natan says: This proof is not necessary, as it says: “And you shall bind them for a sign upon your arm” (Deuteronomy 6:8), and then it states: “And you shall write them upon the doorposts of your house” (Deuteronomy 6:9). This teaches that just as writing is with the right hand, as most people
Rav Ashi said: The requirement that tefillin be donned on the left arm is derived from the verse: “It shall be for a sign upon your arm [yadkha]” (Exodus 13:16), which is written with a letter heh at the end. This is expounded as though it stated: Your weak [keha] arm. R' Abba said to Rav Ashi: But
The Talmud notes that Rav Ashi’s opinion, that the halakha that tefillin are donned on the left arm is derived from the term yadkha, is subject to a dispute between tanna’im, as it is taught in a baraita: Yadkha is written with a heh, indicating weakness, and this is referring to the left arm. Oth
A baraita states: A left-handed person dons tefillin on his right arm, which is equivalent to his left arm, i.e., his weaker arm. The Talmud raises a difficulty: But isn’t it taught in a baraita that a left-handed person dons tefillin on his left arm, which is the left arm of every other person? Aba