Kiddushin 34A

ותפילין.

And the donning of tefillin (Deuteronomy 6:8), which are not worn at night or on Shabbat and Festivals, is also a positive, time-bound mitzva.

ואיזוהי מצות עשה שלא הזמן גרמה ⁠– מזוזה, מעקה, אבידה, ושילוח הקן.

And what is a positive mitzva that is not time bound? Examples include the affixing of a mezuza (Deuteronomy 11:20), the construction of a parapet on a roof (Deuteronomy 22:8), returning a lost item (Deuteronomy 22:1–3), and the release of the mother bird from the nest, i.e., the mitzva of sending away a mother bird when one finds it sitting on chicks or eggs (Deuteronomy 22:6–7).

וכללא הוא? הרי מצה, שמחה, הקהל, דמצות עשה שהזמן גרמא, ונשים חייבות! ותו: והרי תלמוד תורה, פריה ורביה, ופדיון הבן דלאו מצות עשה שהזמן גרמה הוא ⁠– ונשים פטורות!

The Talmud asks: But is this an established principle? But there are the mitzvot of eating matza on the first night of Passover (Exodus 23:15), of rejoicing on a Festival (Deuteronomy 16:9–11), and assembly on Sukkot following the Sabbatical Year (Deuteronomy 31:10–13). And each of these is a positive, time-bound mitzva, and yet women are obligated in them. And furthermore, one can raise a difficulty as follows: But there are the mitzvot of Torah study (Deuteronomy 6:7), procreation (Genesis 1:28), and redemption of the firstborn (Exodus 13:12–13), each of which is not a positive, time-bound mitzva, and yet women are exempt from them.

אמר רבי יוחנן: אין למדין מן הכללות, ואפילו במקום שנאמר בו ״חוץ״,

R' Yoḥanan says: One does not learn practical halakhot from general statements, i.e., when a general statement appears in a Mishnah and uses the term: All, it is not to be understood as an all-inclusive statement without exceptions. This is the case even in a place where it says: Except, to exclude a specific matter.

דתנן: בכל מערבין ומשתתפין חוץ מן המים ומלח, ותו ליכא? והאיכא כמהין ופטריות! אלא אין למדין מן הכללות, ואפילו במקום שנאמר בו ״חוץ״.

A proof for this is as we learned in a Mishnah (Eiruvin 26b): One can establish a joining of houses in courtyards [eiruv ḥatzerot] and a joining of Shabbat boundaries [eiruv teḥumin], and similarly, one can merge courtyards to permit carrying in a joint alleyway on Shabbat. This can be done with all types of food except for water and salt. This is stated as a halakha with specific exceptions, and yet one can ask: Is there nothing else that cannot be used for an eiruv? But there are truffles and mushrooms, which also cannot be used for an eiruv, because they do not offer nourishment. Rather, conclude from this that one may not learn from general statements, even in a place where it says: Except.