The Sages taught: In the case of one who asks a question of a Sage with regard to an issue of ritual impurity and the Sage rules that the item is impure, he may not ask the same question of another Sage and have him rule that it is pure. Similarly, in the case of one who asks a Sage a halakhic question and he deems it forbidden, he may not ask the question of another Sage and have him deem it permitted.
One who asks a sage and is declared impure should not ask another sage to be declared pure
But surely, one could consult all scholars and have them debate, perhaps leading to a change of mind? It is only forbidden for the one asking if they fail to mention to the second Rabbi that they already consulted a first who forbade it. If they disclose this prior consultation, it is permitted. However, the second Rabbi should certainly be cautious about reversing a previous strict ruling. As stated in Niddah 20b, a Rabbi who has forbidden something cannot be overruled by a colleague unless the first Rabbi clearly erred, whether in the text or in their logical reasoning. In such cases, Sanhedrin 6a states that past actions remain valid, but the Rabbi who made the erroneous ruling must compensate from their own funds if they enforced their ruling materially. Specifically, a Rabbi's prohibition cannot be overturned, but a colleague can impose a stricter ruling than a lenient one. However, the Yerushalmi in Shabbat 17:2 recounts that when Rabbi Simon ruled leniently and Rabbi Ami ruled stringently regarding circumcision, Rabbi Simon was upset. The Yerushalmi questions this, citing the baraita that if a Rabbi rules leniently, one should not seek another ruling lest it be stricter. This seems to imply a lenient ruling cannot be overturned! The Yerushalmi clarifies that Rabbi Simon's anger was precisely because there is no basis for such a baraita concerning lenient rulings. The Sages only forbade seeking a second opinion after a strict ruling. Rav Yudan clarifies the incident was the other way around: Rabbi Ami ruled stringently, then Rabbi Simon ruled leniently, and Rabbi Ami was upset, aligning with the baraita about not seeking a lenient ruling after a strict one. Regarding the Gemara in Chulin 49a, where Huna declared an animal treifah and Rav Ada declared it kosher, they were both present in the Beit Midrash when the question arose.
The Gemara asks: But how could Rav Yitzḥak, son of Rav Yehuda, act in this manner? But isn’t it taught in a baraita: In the case of a halakhic authority who deemed an item impure, another halakhic authority is not allowed to deem it pure; if one halakhic authority deemed a matter prohibited, another halakhic authority is not allowed to deem it permitted?
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Áh"S 242:58-63
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