For it was taught: "Michal the daughter of the Kushite wore tefillin and the Sages did not attempt to prevent her, and the wife of Jonah attended the festival pilgrimage and the Sages did not prevent her." Now since the Sages did not prevent her it is clearly evident that they hold the view that (Tefillin) is a positive precept the performance of which is not limited to a particular time.
Had the wearing of a Tefillin be limited to certain times (a time-bound, positive commandment) the wearing of Tefillin by women would be forbidden. Clearly it is neither.
Could it not then here also (regarding Tefillin) be said to be optional? (regarding time, and men can wear them whenever they want) — (the Mishnah) represents rather the view of the following Tanna. For it was taught: “If tefillin are found (on the Sabbath) they are to be brought in, one pair at a time, irrespective of whether the person who brings them in is a man or a woman, and irrespective of whether the tefillin were new or old; so R. Meir. R. Judah forbids this in the case of new ones but permits it in that of old ones.”
Now since their dispute is confined to the question of new and old while in respect of the woman there is no divergence of opinion it may be concluded that (Tefillin) is a positive precept the performance of which is not restricted to a particular time, women being subject to the obligations of such precepts.
And we should also not think that this is limited to Tefillin:
But is it not possible that (the author of this Beriata) holds the same view as R. Jose who ruled: “It is optional for women to lay their hands upon an offering?” (see Lev. 1:4, even though the commandment was given to men) For were you not to say so, how is it that Jonah’s wife attended the festival pilgrimage and the Sages did not prevent her, seeing that there is no one who contends that the observance of a festival is not a positive precept the performance of which is limited to a particular time? You must consequently admit that he holds (the Festival pilgrimage) to be optional (and thus women can perform it)
All this is radical today, by the way, only to certain circles. Liberal Jews have known and accepted this reading for decades. There really is no reason to hold on to the idea that women must be restricted in the observance of Jewish ritual commandments.