The Process and Limits of Radical Change Parshat Re'eh

(2) You shall not add anything to what I command you or take anything away from it, but keep the commandments of the LORD your God that I enjoin upon you.

(11) You shall act in accordance with the instructions given you and the ruling handed down to you; you must not deviate from the verdict that they announce to you either to the right or to the left.

Why is the shofar sounded not during the recitation of the Amidah and sounded during the recitation of the Amidah? In order to confuse the satan. [Concerning the matter] the Tosafot raised the objection that [sounding the shofar twice] constitutes a violation of "not adding" (Bal tosif)...

And they, of blessed memory, explained that Bal Tosif does not apply to the fulfillment of a mitzvah twice...And they of blessed memory...never claimed that Bal tosif applies except when one adds on their own (mi-da'at atzmo), as, for example, a priest who adds his own benediction...

But concerning anything that the sages ordained for some cause (tikkenu le-tzorekh), the prohibition of Bal tosif does not apply, for the Torah already states "According to the instruction which they render, etc." (Deuteronomy 17:11)...

Therefore, they are empowered to enact an addition (gozerin u-mosifin) for some reason. And the same is true of Bal tigra ("not taking away") for a reason, as, for example, Rosh Hashanah that falls on Shabbat, concerning which they decreed with reason not to sound the shofar, even though the Torah requires that it be sounded. Here too [i.e., the sounding of the shofar twice] they saw some cause to sound it once and then again, and it is a mitzvah to obey the words of the sages from the verse "You shall not deviate (Lo tasur)" (Deuteronomy 17:11). (Halakhic Process, 157-158)

Since the court may make an enactment that forbids that which is permissible (and its forbidden nature becomes permanent), and may, as well, permit temporarily (le-fi-sha'ah) matters that are forbidden according to the Torah, what is the meaning of the Torah's warning, "You shall not add to it, nor take away from it"(Deuteronomy 13:1)? [It means] that one may neither add to the words of the Torah nor diminish from them, and establish that matter in perpetuity as from the Torah, either concerning the written or the oral Torah. How?

It is written in the Torah: "You should not cook a kid in it's mother's milk" (Exodus 23:19). On the basis of tradition we have learned that this verse forbids the cooking and eating of meat and milk, both the meat of domesticated animals (behemah) and of beasts of chase (chayyah), but that the meat of poultry with milk is permissible from the Torah. If some court were to declare the meat of beasts of chase with milk permissible that would be taking away. And if it were to forbid the meat of fowl [with milk] by maintaining that it is included in the category of "kid," and is forbidden from the Torah, that would be adding. But if [the court] said, "The meat of fowl is permissible from the Torah, but we forbid it; and we shall inform the people that it is an enactment, in order that the matter not bear negative results, that people might say that fowl is permissible, since it is not stated explicitly, and someone else will claim that the meat of domesticated animals is also permissible, except for goats; and some else will claim that even the meat of goats is permissible in the milk of a cow or a ew, since naught is stated other than "its mother," who is of the same species; and yet another will claim that [even the meat of a goat] is permissible save in its own mother's milk, since only its mother is stated explicitly, therefore, we forbid all meat with milk , even the meat of fowl," this is not adding but putting up a fence around the Torah. And so anything similar. (Halakhic Process, 159-160)

(3) A widow may only collect [the debt owed from her ketubah, monetary settlement payable to a married woman upon divorce or the death of her husband] from the property of orphans by [taking] an oath. They stopped imposing an oath; Rabban Gamliel the Elder enacted that she may make a vow with regard to whatever they desire, and collects her ketubah. Witnesses sign on a bill of divorce, due to Tikkun HaOlam. Hillel instituted the pruzbul due to Tikkun HaOlam.

(3)Any loan made with a Pruzbul is not canceled. This is one of the matters that Hillel the elder instituted. When he observed that the nation withheld from lending to each other and were transgressing what is written in the Torah (Deuteronomy 15:9): "Beware lest there be in your mind a base thought," he instituted the Pruzbul.