Halakhah su Giudici 1:37

Nevertheless, this objection is overruled: First of all after the destruction of the Holy Temple during the time of the Tannaim (the sages of the Mishnaic era) and the Amoraim (the sage of the Talmudic era) and the Gaonim (the sage of the post Talmudic era) Techelet was found. And at that point we were already exiled from our land and it was impossible to pay the tribe of Zevulun for the Hillazon, so therefore only when Israel were dwelling on their land and each tribe was living on their appointed portion and the Hillazon was in the portion of Zevulun and then if one took the Hillazon without the knowledge of Zevulun and without payment it was considered as theft, it was during that period of time specifically that the promise was made as can be learned from the text, there they will offer up the sacrifices of righteousness (that is regarding theft). But because of our transgression, since we have been exiled from our land and the nations have gained a foothold in all of the land of Israel until the end of days when He will return us and have compassion upon us and bring us back to Zion with exultation speedily in our, time this promise is not pertinent for the tribe of Zevulun does not dwell there but we can say its theft. And furthermore even when Israel was dwelling on their land only if the Hillazon that went up to the mountains in the portion of Zevulun was taken without payment then the dyeing process would not work and would be of no avail for it would be considered as theft. But in truth the Hillazon is found in all the western and Mediterranean seas but can only be caught with difficulty, Whereas in the portion of Zevulun the Hillazon rose from the sea unto its mountains that sloped to the sea and there would multiply and would easily be caught as well be explained with G-d's help. It appears that certainly if the Hillazon would be caught from the sea even in the portion of Zevulun without payment the dye would not be ruined. and this is what Rashi explains (ibid). Everyone will need you, all your brothers will need you for the Hillazon that rises from the sea unto the mountains, the nations will call out to the mountains. From all the tribes they will gather together on your mountains to bury the Hidden Treasures of the sand. This is said only regarding the rest of other tribes that the Hillazon was found in the portion of Zevulun because they would go up to his mountains or we mentioned above, and all the tribes needed him to buy form him the Techelet. But certainly the Techelet was found in all the western and Mediterranean seas and all the nations that encamped by the sea had the Hillazon and is written in the text in (Yechezkiel 27) Techelet and argamon are from Islands of Alisha etc. The majority of Techelet was from the island of Alisha and the merchants of Shva, Asher and Kalmud-- and was not considered part of the land of Israels Techelet. For in truth they only had enough to supply themselves with garments for the royalty, princes and priests and for the fulfillment of the precept of Techelet but they did not have enough Techelet to sell to the outside world. If this being so how is it that the dyeing process was successful if they took the Hillazon without paying for it and did not offer it from the tribe of Zevulun, but certainly we mentioned above that where was trapped within the portion of Zevulun would not be ruined. And it also appears from what is learned in Tractate Sotah (46B) regarding the following passage in (Judges 1) And the man went to the land of the Chittim and he built a city and called its name Luz and this is its name till this very day. The Midrash in Breshit Rabba explains that Luz is where the Techelet was dyed. The city in the land of the Chittim appears to not have been inhabited by the Jews for it is not part of the land of Israel and it was a place where the Techelet was found and the dyeing process successfully done. Even though they did not pay the tribe of Zevulun for it that is as mentioned above because it was not taken from his portion and all this is clear and correct.

Teshuvot Shevut Ya'akov, III, no. 71,⁴⁶Shevut Ya‘akov also adduces proof that ẓa‘ar ba‘alei ḥayyim is permitted, at least for medical purposes, on the basis of the statement of the Gemara, Shabbat 77b, to the effect that various insects were created so that, when crushed, they might be used as remedies for various bites and that serpents were created so that they might be boiled and used as a cure for eruptions; see above, note 33. As additional evidence, he cites the statement of the Gemara, Shabbat 109b, advising that if one is bitten by a snake “he should procure an embryo of a white ass, tear it open, and be made to sit upon it.” A further source which may be cited is the statement of the Gemara, Shabbat 110b, dealing with the treatment of jaundice, which advises, inter alia, “let him take a speckled swine, tear it open and apply it to his heart.” However, these sources fail to demonstrate that ẓa‘ar ba’alei ḥayyim is permitted for medical purposes if the killing of animals is excluded from the prohibition; see above, notes 21-25 and accompanying text. and Teshuvot Rav Pe'alim, I, Yoreh De'ah, no. 1, find support for Rema's ruling in the Mishnah, Avodah Zarah 13b. It is forbidden to sell a solitary white chicken to an idolator for fear that he may intend to offer the bird as a pagan sacrifice. However, since a mutilated bird would not be used for idolatrous purposes, the Mishnah permits the seller to render the chicken unfit for sacrificial use by removing a digit from the chicken's foot prior to sale. Here, too, such a procedure necessarily entails pain to the chicken. Accordingly, argue Shevut Ya'akov and Rav Pe'alim, such a practice could be permitted only because it is prompted by legitimate commercial need. The procedure sanctioned by the Mishnah serves as a paradigm establishing the general principle that za'ar ba'alei ḥayyim is permissible when necessary to satisfy a human need.⁴⁷See, however, R. Yechiel Ya‘akov Weinberg, Seridei Esh, III, no. 7, and Ḥelkat Ya‘akov, III, no. 31, sec. 4. Rabbi Weinberg argues that this source cannot serve as a basis for Rema’s ruling since “perhaps” such practices are condoned only for the purpose of preventing idolatrous activities. Cf. Ramban, Avodah Zarah 13b. In his analysis of the Gemara’s citation of the verse “and their horses shall you hough (et suseihem te‘aker)” (Judges 1:6), Ramban equates abrogation of idolatrous practices with other human needs. See also Teshuvot Imrei Shefer, no. 34, sec. 9, who endeavors to show that ẓa‘ar ba‘alei ḥayyim was permitted in the case of the white chicken sold to an idolator only to spare the animal from even greater pain. The same authority, loc. cit., no. 34, sec. 14, also suggests that this procedure was permitted only when performed in a manner which does not entail pain; see below, note 52. A similar explanation is advanced by Ḥavalim ba-Ne‘imim, I, no. 43, sec. 3.