Our Gemara on Amud Aleph noticed a problematic halakha in the Mishna. There is a three month rule regarding a woman who was married prior. She cannot marry a second man until after three months in order to avoid confusion about paternity of the child. The Mishna tells us of a case of two brides who already had Kiddushin but accidentally got mixed up at the time of nisuin. If they were minors and unable to get pregnant, they can return to their husbands immediately without the usual 3 month waiting period.

The Gemara wonders why this Mishna rules accordingly when, in actuality, the standing position is to apply the waiting period across the board, even in regard to minors who cannot get pregnant in order to maintain standardization of the Halakha.

The Gemara suggests an answer, based on a tradition from Rav Gidal in the name of Rav. The Mishna does not represent halakhic precedent, but rather was a one-time ruling for a particular reason. This answer was eventually dismissed for linguistic reasons within the text, so the Gemara did not explore what possible extenuating circumstances could have been behind the proposed extra-legal ruling that allowed the young brides to immediately return to their husbands.

The Gemara uses a term to describe this ruling: Hora’as Sha’ah, which literally translates as, “A ruling of the moment.” This is based on the idea that the Sanhedrin had the legal power to make temporary rulings that abrogate normative halakha, based on exigencies of the moment.

What is the halakha of hora’as sha’ah? Rambam in Laws of Rebels (2:4) codifies it as follows:

[The Sanhedrin] has the authority to abrogate the dictates of the Torah as a temporary measure.

What is implied? If a court sees that it is necessary to strengthen the faith and create a safeguard so that the people will not violate Torah law, they may apply beatings and punishments that are not sanctioned by Torah. They may not, however, establish the matter for posterity and say that this is the halachah.

Similarly, if they saw that temporarily it was necessary to nullify a positive commandment or violate a negative commandment in order to bring people at large back to the Jewish faith or to prevent many Jews from transgressing in other matters, they may do what is necessary at that time. To explain by analogy: Just like a doctor may amputate a person's hand or foot so that the person as a whole will live; so, too, at times, the court may rule to temporarily violate some of the commandments so that they will later keep all of them. (Translation Eliyahu Touger, Chabad.org, with some modifications by me.)

By his amputation analogy, the Rambam implies  a logical rationale for this halakha. For any legal system to survive, there needs to be a court that has the authority to occasionally make a temporary adjustment or some modifications daptation in response to unusual unforeseeable circumstances. This court indeed does not have the authority to make permanent changes, however it does have the ability to make temporary enactments, overturning prior rabbinic edits and even Torah law as needed for expedience.

The Sefas Emes (Korach 18, 5653) offers a deeper explanation.  The Torah in its given form was channeled from Moshe and delivered to the Jewish people in the form that was appropriate for them.  However, there are other expressions of Torah ideas, that are applications of different truths, that may manifest themselves under certain temporary circumstances.  This takes the form of a hora’as sha’ah.

The Sefas Emes’ idea about Torah can be understood by the following metaphor.  Mathematics are based on certain universal truths.  You can build a building using equations based on those truths.  However, you can also build an entirely different structure, if that was necessary, in a different environment, using the same engineering and mathematical principles. 

There is an intriguing Aggadah which supports this point (Pirke DeRebbi Eliezer 46:4):

The ministering angels said to him: Moshe ! This Torah has been given only for our sakes. Moses replied to them: It is written in the Torah, "Honour thy father and thy mother" (ibid. xx. 12). Have ye then father and mother? Again, it is written in the Torah, "When a man dieth in the tent" (Num. xix. 14). Does death happen among you? They were silent, and did not answer anything further.

The obvious question is what were the ministering angels thinking? A school age child could have argued Moshes’ point! Rather, there must be a given assumption that the divine truths of the Torah, if received by the angels, would be expressed differently. Moses did not so much refute the angels as he calmed them down - once they realized he was receiving a HUMAN version of the Torah, which reflected the same truths as theirs, but still was not expressed or revealed in the same manner.

We also find this expressed in Midrash Tanhuma (Yisro, 16):

Levi said: The Holy One appeared to them as an image with faces on every side. If a thousand people were looking at it, it would be looking back at all of them. So it is with the Holy One. When he spoke, each and every person of Israel said: The Divine Word has been with me alone...R. Jose bar Hanina said: It was according to the capacity of each and every person that the Divine Word spoke with him, and do not be surprised at this fact. Since we find in the case of the manna that, when it came down to Israel, each one of them savored it according to his capacity, how much the more would the principle apply with the Divine Word!

It is notable the difference in approaches between Rambam and Sefas Emes.  The Rambam, who often explains Torah ideas in rational terms, has no problem considering the practical necessities of law and society as sufficient justification for the legal concept of hora’as sha’ah.  However, the Sefas Emes cannot abide by such a cold, dry idea.  It would seem, if the Torah is God’s perfect guidance for humans, it should have the ability to take into account every contingency. Otherwise, God forbid, the Torah would be flawed.  Therefore, we must understand that even the temporary edicts to be serving some expression of Torah wisdom.  This contrast between the mystical and rational approach parallels our discussion about reasons foe the commandments in Psychology of the Daf, Yevamos 33.

Regardless of the philosophical underpinnings, hora’as sha’ah was a critical and powerful tool in the hands of Sanhedrin to help the Torah community buffer and weather various contingencies that arise over time, without being struck in restrictive and rigid responses.  It would take wisdom and conservatism to know when to temporarily suspend or enact a law, and when to hold the line. Yet, in actuality at times the they asserted their power. 

What shall we do nowadays when there is no Sanhedrin to assist in managing our obligations toward Torah law, and potential conflicts that arise in society’s needs? Basically, we are powerless and can only take psychological comfort in the notion that if some aspects of Torah observance seem out of date in comparison to societal needs, at least the Torah had built in a process to manage it, even if now we can no longer enact it.  A more conservative mystical approach might argue that this too must be God’s will.  If there is no Sanhedrin nowadays, then there is no need for the Sanhedrin, and whatever the Torah expects of us is the product of flawless divine wisdom. According to that argument, nowadays we are meant to work within the Torah’s requirements and not make any allowances or adjustments.  However, Rav Kook in Shemoneh Kevatzim (2:30) says something that is logical and a defacto truth, but nonetheless spectacularly mind blowing. He uses the idea of. Divine will in the opposite direction. He suggests that there is an unconscious mass-level substitute for hora’as sha’ah:

לפעמים יש צורך בהעברה על דברי תורה, ואין בדור מי שיוכל להראות את הדרך, בא הענין על ידי התפרצות. ומכל מקום יותר טוב הוא לעולם שיבוא ענין כזה על ידי שגגה, ובזה מונח היסוד של מוטב שיהיו שוגגין ואל יהיו מזידין. רק כשהנבואה שרויה בישראל אפשר לתקן ענין כזה על ידי הוראת שעה, ואז נעשה בדרך היתר ומצוה בגלוי. ועל ידי סתימת אור הנבואה, נעשה תיקון זה על ידי פרצה, שמדאבת את הלב מצד עצמה, ומשמחת אותו מצד תכליתה.

At times, when there is a need to disregard words of Torah but there is no one in the generation who can show the way, the matter comes about by means of a disruption. At any rate, it is better for the world that such a matter come about by means of an error. In this inheres the principle, “Better that people [do wrong] in error and not with purposeful intent” (Beitsah 30b). Only when prophecy is present in [the nation of] Israel is it possible to institute such a matter – by means of a temporary injunction. Then it is done openly, with permission and as a Godly command. But in consequence of the sealing of the light of prophecy, this rectification come about by means of a [longlasting] disruption that, although it dismays the heart from the aspect of its outer being, causes it to rejoice from the aspect of its inner being.

So just as it is divine will that there is no Sanhedrin, nevertheless through the collective unconscious wisdom of the Jewish people, God’s will is realized anyhow when internal forces, customs and sensibilities seem to slowly cause a different halakhic response.