מלך כשופט ומחוקק (חלק ג') - דרשות הר"ן ב'

The court has the power to suspend even these rules for a term even if it is lesser than the earlier court, for these [rabbinic] decrees must not be more rigorous [in their application] than Torah law. Any court has the authority to suspend the law in an emergency. How so? A court that determines that to strengthen the law/religion and to make a fence so that the masses do not violate Torah law, has the authority to flog [offenders] without warrant authorized by positive law. But they do not establish this [deflection] from positive statute in permanence and do not declare that such and such is the law. And similarly, if they [the members of the court] determine to nullify [le-batel] a positive commandment or to transgress a negative commandment in order to cause the masses to return to law/religion or to prevent the majority of Israel from stumbling [i.e., sinning] in other [similarly serious] matters, [the court] does so [suspend the positive law]. For just as the doctor amputates a limb or foot in order that a patient survives, similarly, the court rules at any time to transgress a few commandments for a term in order that the masses may one day return and fulfil [all] the commandments. Thus, any court may rule, at any time [zeman min ha-zemanim], to violate some commandments temporarily, in order to sustain them all [i.e., all of the commandments], as was commanded40 by the early sages, violate one Sabbath so that one may observe many Sabbaths.

The Gemara answers that this was established through a certain incident, as that incident occurred in which a man named bar Ḥama killed a person. The Exilarch said to Rav Abba bar Ya’akov: Go investigate this case, and if he certainly killed him, let them put his eyes out. Subsequently two witnesses came and testified that he certainly killed him. Bar Ḥama then went and brought two other witnesses, who testified about one of those first witnesses. One said: He stole, in my presence, a kav of barley; and one said: He stole, in my presence,