Eruvin 97A

אחד חדשות ואחד ישנות, דברי רבי מאיר. רבי יהודה אוסר בחדשות ומתיר בישנות. אלמא מר סבר טרח איניש, ומר סבר לא טרח איניש.

and whether the tefillin are new or old; this is the statement of R' Meir. R' Yehuda prohibits carrying new tefillin but permits carrying old ones. Apparently, one Sage, R' Yehuda, holds that a person exerts himself to fashion an amulet that looks like tefillin, and one Sage, R' Meir, holds that a person does not exert himself for this purpose, and therefore something that has the appearance of tefillin must be tefillin.

(שיצ״י עצב״י סימן.) והשתא דתני אבוה דשמואל בר רב יצחק: אלו הן ישנות ⁠— כל שיש בהן רצועות ומקושרות, חדשות ⁠— יש בהן רצועות ולא מקושרות. דכולי עלמא לא טרח איניש.

Shin, yod, tzadi, yod, ayin, tzadi, beit, yod is a mnemonic for the statements that follow. The Talmud adds: And now that the father of Shmuel bar Rav Yitzḥak has taught that these are deemed old tefillin: Any that have straps that are permanently tied in the manner of tefillin, and new tefillin are those that have straps that are not tied, the conclusion is that everyone agrees that a person does not exert himself to fashion an amulet similar to tefillin or string-like tzitzit. They disagree with regard to new tefillin that are not tied properly and cannot be donned in a manner typical of a weekday. The reason is that tying a permanent knot on Shabbat is prohibited by Torah law. Therefore, these tefillin may not be donned, and R' Zeira’s opinion is accepted.

וליענבינהו מיענב! אמר רב חסדא: זאת אומרת, עניבה פסולה בתפילין.

The Talmud asks a question with regard to R' Yehuda’s opinion that new tefillin may not be brought into town because they lack a permanent knot: Why must one tie the tefillin with a knot? Let him simply tie a bow, which is not prohibited on Shabbat, and place the tefillin on his head and arm in that manner. Rav Ḥisda said: That is to say that a bow is invalid for tefillin, as a proper knot is required.