Halacha

הלכה א
גִּיד הַנָּשֶׁה נוֹהֵג בִּבְהֵמָה וְחַיָּה הַטְּהוֹרִין וַאֲפִלּוּ בִּנְבֵלוֹת וּטְרֵפוֹת שֶׁלָּהֶן. וְנוֹהֵג בְּשָׁלִיל וּבְמֻקְדָּשִׁין בֵּין קָדָשִׁים הַנֶּאֱכָלִים בֵּין קָדָשִׁים שֶׁאֵינָן נֶאֱכָלִין. וְנוֹהֵג בְּיָרֵךְ שֶׁל יָמִין וּבְיָרֵךְ שֶׁל שְׂמֹאל. וְאֵין אָסוּר מִן הַתּוֹרָה אֶלָּא שֶׁעַל כַּף הַיָּרֵךְ בִּלְבַד שֶׁנֶּאֱמַר (בראשית לב לג) "אֲשֶׁר עַל כַּף הַיָּרֵךְ". אֲבָל שְׁאָר הַגִּיד שֶׁלְּמַעְלָה מִן הַכַּף וְשֶׁלְּמַטָּה עַד סוֹפוֹ וְכֵן חֵלֶב שֶׁעַל הַגִּיד אֵינוֹ אָסוּר אֶלָּא מִדִּבְרֵי סוֹפְרִים. וּשְׁנֵי גִּידִין הֵן. הַפְּנִימִי הַסָּמוּךְ לָעֶצֶם אָסוּר מִן הַתּוֹרָה. וְהָעֶלְיוֹן כֻּלּוֹ אָסוּר מִדִּבְרֵיהֶם:
כסף משנה
1.
[The prohibition against partaking of] the gid hanesheh1Genesis, ch. 32, relates that before his confrontation with Esau, Jacob remained alone in his camp. An unidentified being - interpreted by the Torah commentaries to be Esau's archangel - wrestled with him the entire night. When he saw that he could not defeat Jacob, he gave him a blow to his upper thigh, dislocating his gid hanesheh. In commemoration of this event, "The children of Israel do not eat the gid hanesheh.
The Rabbis identified the gid hanesheh as the sciatic nerve, the large main nerve running down the back of an animal's hind leg. The term gid, though sometimes translated as "sinew," is a general term. As the Rambam writes in his Commentary to the Mishnah (Zevachim 3:4), it is used to refer to arteries, veins, tendons, nerves, and sinews.
applies with regard to kosher2See Halachah 5. domesticated animals and wild beasts,3Sefer HaMitzvot (negative commandment 183) and Sefer HaChinuch (mitzvah 3) include this prohibition among the 613 mitzvot of the Torah. even nevelot and trefot.4See Halachah 6. It applies to a fetus5The Shulchan Aruch (Yoreh De'ah 65:7 does not cite the Rambam's view, but instead quotes two differing opinions: one that the prohibition does not apply to a fetus at all and another, that it applies only when the fetus has completed the period of gestation and is discovered alive. and to animals that have been consecrated, both those consecrated [for sacrifices] of which we partake and for sacrifices of which we do not partake. It applies to [the gid] on the right thigh and that on the left thigh.6Although the angel only dislodged the nerve on one of Jacob's legs, we are forbidden to partake of the nerves from both sides.
According to Scriptural Law, only [the gid] on the hip socket is forbidden, as [Genesis 32:33] states: "which is on the hip-socket." The remainder of the gid which is above the socket or below the socket - and similarly, the fat which is on the gid - are forbidden only according to Rabbinic decree.7See Halachah 7 concerning the removal of this nerve. There are two giddim. The inner one next to the bone is forbidden according to Scriptural Law. The entire outer one is forbidden by Rabbinic decree.

הלכה ב
הָאוֹכֵל מִגִּיד הַנָּשֶׁה הַפְּנִימִי מִמָּקוֹם שֶׁעַל הַכַּף לוֹקֶה. וְאִם אָכַל מֵחֶלְבּוֹ אוֹ מִשְּׁאָר הַגִּיד הַפְּנִימִי אוֹ מִכָּל הַחִיצוֹן מַכִּין אוֹתוֹ מַכַּת מַרְדּוּת. וְכַמָּה שִׁעוּר אֲכִילָה. כְּזַיִת. וְאִם אָכַל הַגִּיד שֶׁעַל הַכַּף כֻּלּוֹ אַף עַל פִּי שֶׁאֵין בּוֹ כְּזַיִת לוֹקֶה מִפְּנֵי שֶׁהוּא כִּבְרִיָּה בִּפְנֵי עַצְמָהּ:
כסף משנה
2.
When a person partakes of the inner gid hanesheh on the socket, he is liable for lashes.8Because he violates a Scriptural prohibition. If he partakes of the fat [of the gid], the remainder of the inner gid, or the entire outer one, he is liable for stripes for rebellious conduct.9For violating a Rabbinic prohibition.
What is the measure of which one must partake to be liable? An olive-sized portion. If one ate the entire gid on the socket, one is liable, even though it is less than an olive in size. The rationale is that it is considered as a self-contained entity.10Accordingly, even if it is less than an olive-sized portion in size, one is liable. Compare to Chapter 2, Halachah 21, Chapter 15, Halachah 17, and Chapter 16, Halachah 6.

הלכה ג
אָכַל כְּזַיִת מִגִּיד שֶׁל יָמִין וּכְזַיִת מִגִּיד שֶׁל שְׂמֹאל. אוֹ שֶׁאָכַל שְׁנֵי גִּידִים כֻּלָּן. אַף עַל פִּי שֶׁאֵין בָּהֶן כְּזַיִת לוֹקֶה שְׁמוֹנִים. (וְכֵן הוּא לוֹקֶה עַל כָּל גִּיד וְגִיד):
כסף משנה
3.
When a person eats an olive-sized portion of the gid on the right side and an olive-sized portion of the gid on the left side, or he ate two entire giddim even if they are not the size of an olive, he receives 80 lashes. He is given lashes for every gid independently.11Rav Moshe HaCohen writes that this ruling applies when the person was given a separate warning for each gid. Otherwise, he receives only one set of lashes. The Maggid Mishneh states that the Rambam would also accept that interpretation.

הלכה ד
הָעוֹף אֵין בּוֹ מִשּׁוּם גִּיד הַנָּשֶׁה מִפְּנֵי שֶׁאֵין לוֹ כַּף יָרֵךְ אֶלָּא יְרֵכוֹ אָרֹךְ. וְאִם נִמְצָא עוֹף שֶׁיְּרֵכוֹ כְּיֶרֶךְ הַבְּהֵמָה שֶׁיֵּשׁ לוֹ כַּף גִּיד הַנָּשֶׁה שֶׁלּוֹ אָסוּר וְאֵין לוֹקִין עָלָיו. וְכֵן בְּהֵמָה שֶׁכַּף יְרֵכָהּ אָרֹךְ כְּשֶׁל עוֹף גִּיד הַנָּשֶׁה שֶׁלָּהּ אָסוּר וְאֵין לוֹקִין עָלָיו:
כסף משנה
4.
The prohibition against gid hanesheh does not apply with regard to a fowl, because it does not have a [round]12This explanatory addition is based on Chullin 92b. hip-socket. Instead, its thigh is long [and flat]. If there is a fowl whose thigh is shaped like that of the thigh of an animal, i.e., it has a hip-socket, its gid hanesheh is forbidden, but one is not liable for lashes, because of it. Similarly, when there is an animal whose thigh is long like that of a fowl, its gid hanesheh is forbidden, but one is not liable for lashes for it.13Chullin 92b discusses these issues and leaves both matters unresolved; hence, the Rambam's rulings.

הלכה ה
הָאוֹכֵל גִּיד הַנָּשֶׁה מִבְּהֵמָה וְחַיָּה הַטְּמֵאִים פָּטוּר לְפִי שֶׁאֵינוֹ נוֹהֵג בִּטְמֵאָה אֶלָּא בִּבְהֵמָה שֶׁכֻּלָּהּ מֻתֶּרֶת. וְאֵינוֹ כְּאוֹכֵל מִשְּׁאָר גּוּפָהּ שֶׁאֵין הַגִּידִים מִכְּלַל הַבָּשָׂר כְּמוֹ שֶׁבֵּאַרְנוּ. וְאִם אָכַל מֵחֵלֶב שֶׁעַל הַגִּיד הֲרֵי זֶה כְּאוֹכֵל מִבְּשָׂרָהּ:
כסף משנה
5.
When a person eats the gid hanesheh from a non-kosher domesticated animal or wild beast, he is not liable.14Not for partaking of the gid and not for partaking of the meat of a forbidden animal. [The rationale is that this prohibition] does not apply with regard to a non-kosher animal,15Chullin 101a notes that the confrontation between Jacob and the angel took place before the Giving of the Torah, at a time when the Jews could eat non-kosher animals. Hence, there is reason to say that the prohibition could involve a non-kosher animal, for partaking of such animal was not forbidden until the Giving of the Torah.
In response, the Talmud explains that our observance of this prohibition does not stem from the practice observed by Jacob's descendants, but because this prohibition was reiterated at the time of the Giving of the Torah. In his Commentary to the Mishnah (Chullin 7:6, the Rambam elaborates on this point, explaining that our observance of Jewish practice, even the mitzvot which we know that the Patriarchs fulfilled like circumcision, stems from God's command at Sinai and not from our ancestors' observance.
only with regard to an animal that is entirely permitted. Nor is he considered as one who partook of the remainder of its body, for the gid is not included as meat, as we explained.16Chapter 4, Halachah 18. See the Shulchan Aruch (Yoreh De'ah 65:9) which states that a gid is "like a piece of wood; it has no flavor." If, however, one partakes of the fat on the gid [of a non-kosher] animal, it is considered as if one ate from its meat.

הלכה ו
הָאוֹכֵל גִּיד הַנָּשֶׁה שֶׁל נְבֵלָה אוֹ שֶׁל טְרֵפָה אוֹ שֶׁל עוֹלָה חַיָּב שְׁתַּיִם. מִתּוֹךְ שֶׁנִּכְלָל בְּאִסּוּר שְׁאָר גּוּפָהּ שֶׁהָיָה מֻתָּר נִכְלָל גַּם הַגִּיד וְנוֹסָף עָלָיו אִסּוּר אַחֵר:
כסף משנה
6.
When a person partakes of a gid hanesheh from a nevelah, a trefe, or an animal consecrated as a burnt offering, he is liable for two [sets of lashes]. Since [the prohibition]17I.e., the prohibition against partaking of a nevelah, trefe, or burnt offering. includes the remainder of its body which was permitted, it also includes the gid and causes another prohibition to be added to it.18Following the concept of issur kollel, "an encompassing prohibition," as explained in the conclusion of Halachah 14 (Maggid Mishneh).
The Kessef Mishneh questions the Rambam's ruling, noting that Chullin 82b states that according to the opinion that a gid hanesheh does not have any flavor, one is not liable. Only the opinion that maintains that the gid hanesheh does have a flavor holds one liable. From the previous halachah, it appears that the Rambam follows the former view. Why then does he hold the person liable for two sets of lashes.

הלכה ז
הַנּוֹטֵל גִּיד הַנָּשֶׁה צָרִיךְ לְחַטֵּט אַחֲרָיו עַד שֶׁלֹּא יַשְׁאִיר מִמֶּנּוּ כְּלוּם. וְנֶאֱמָן הַטַּבָּח עַל גִּיד הַנָּשֶׁה כְּשֵׁם שֶׁנֶּאֱמָן עַל הַחֵלֶב. וְאֵין לוֹקְחִין בָּשָׂר מִכָּל טַבָּח אֶלָּא אִם הָיָה אָדָם כָּשֵׁר וּמֻחְזָק בְּכַשְׁרוּת הוּא שֶׁשּׁוֹחֵט לְעַצְמוֹ וּמוֹכֵר וְנֶאֱמָן:
כסף משנה
7.
One who removes the gid hanesheh must ferret out all traces of it until nothing remains.19Since the gid hanesheh and the gid forbidden by Rabbinic decree subdivide into several branches, this is a rather difficult task. For this reason, in most sectors of the Jewish community today, it is customary not to eat the hind-quarters of an animal. Accordingly, several cuts of meat, e.g., sirloin steak, are not available from kosher butchers. A butcher's word is accepted with regard to the gid hanesheh,20I.e., we rely on his word and do not inspect the meat ourselves. just as it is accepted with regard to forbidden fat. [Accordingly,] we do not purchase meat from every butcher, [only from] an upright man who has established a reputation for observance.21If the person himself does not have a reputation for observance and knowledge of the laws, he can sell meat if he hires such a person to act as a supervisor. This is the rationale for the practice of hasgachah, kashrut inspection, practiced today. If he slaughters meat himself and sells it, his word is accepted.

הלכה ח
בַּמֶּה דְּבָרִים אֲמוּרִים בְּחוּצָה לָאָרֶץ. אֲבָל בְּאֶרֶץ יִשְׂרָאֵל בִּזְמַן שֶׁכֻּלָּהּ לְיִשְׂרָאֵל לוֹקְחִין מִכָּל אָדָם:
כסף משנה
8.
Where does the above apply? In the Diaspora. In Eretz Yisrael, by contrast, when it is populated entirely by [Torah-observant] Jews, meat may be purchased from anyone.22In the present era, there is no difference between Eretz Yisrael and other lands, for the majority of the inhabitants of Eretz Yisrael are not Torah observant.

הלכה ט
טַבָּח הַנֶּאֱמָן לִמְכֹּר בָּשָׂר וְנִמְצָא בְּשַׂר נְבֵלָה אוֹ בְּשַׂר טְרֵפָה יוֹצֵא מִתַּחַת יָדוֹ. מַחֲזִיר אֶת הַדָּמִים לַבְּעָלִים ומְשַׁמְּתִין אוֹתוֹ וּמַעֲבִירִין אוֹתוֹ. וְאֵין לוֹ תַּקָּנָה לְעוֹלָם לִקַּח מִמֶּנּוּ בָּשָׂר עַד שֶׁיֵּלֵךְ לְמָקוֹם שֶׁאֵין מַכִּירִין אוֹתוֹ וְיַחֲזִיר אֲבֵדָה בְּדָבָר חָשׁוּב אוֹ יִשְׁחֹט לְעַצְמוֹ וְיוֹצִיא טְרֵפָה לְעַצְמוֹ בְּמָמוֹן חָשׁוּב שֶׁוַּדַּאי עָשָׂה תְּשׁוּבָה בְּלֹא הַעֲרָמָה:
כסף משנה
9.
[The following rules apply when] a butcher is considered as trustworthy to sell meat, but it is discovered that he sold meat that was nevelah or trefe. He must return the money to its owners.23He must return the money entirely. This applies even if the customers already partook of the non-kosher meat (Hilchot Mechirah 16:14). The rationale is that a person's soul is revolted by the commission of a transgression and he is not considered to have benefited from the meat at all (Sefer Meirat Einayim 232:4). He is placed under a ban of ostracism and is removed from his position.24See Chapter 7, Halachah 21.
There is no way that he can correct [his act] so that people [will be allowed] to purchase meat from him until he goes to a place where his identity is unknown25If he performs such an act in a place where his identity is known, it can be said that he did so in order to be reinstated.and returns a lost object of significant worth or slaughters an animal for his own self and has it declared trefe although it involves a significant financial loss. For these actions indicate that he certainly repented without any [intent to] deceive.26I.e., they show that he is willing to forgo his financial benefit in order to keep Torah law. See also Hilchot Shechitah 10:14 and Hilchot Edut 12:9 which deal with the same concept. Hilchot Edut states that in order to be accepted as a witness, he must wear black garments as a sign of repentance.

הלכה י
הַלּוֹקֵחַ בָּשָׂר וּשְׁלָחוֹ בְּיַד אֶחָד מֵעַמֵּי הָאָרֶץ הֲרֵי זֶה נֶאֱמָן עָלָיו. וְאַף עַל פִּי שֶׁאֵינוֹ מֻחְזָק בְּכַשְׁרוּת אֵין חוֹשְׁשִׁין לוֹ שֶׁמָּא יַחֲלִיף. וַאֲפִלּוּ עַבְדֵי יִשְׂרָאֵל וְאַמְהוֹתֵיהֶן נֶאֱמָנִין בְּדָבָר זֶה. אֲבָל לֹא עַכּוּ''ם שֶׁמָּא יַחֲלִיף:
כסף משנה
10.
When a person purchases meat and sends it via a common person, [the latter's] word is accepted with regard to it. Although he has not established a reputation for Torah observance,27See the Maggid Mishneh who maintains that the Rambam would rule in this manner even when a Jew is reputed to transgress various prohibitions. He also mentions the opinion of the Rashba who maintains that further precautions must be taken if an article is entrusted to a non-observant Jew. The Shulchan Aruch (Yoreh De'ah 118:8) quotes the Rambam's ruling and then cites the Rashba's view without indicating which opinion should be followed. we do not suspect that he will exchange [the meat for a non-kosher cut].28I.e., we do not expect that he will steal. Moreover, he will derive no benefit from doing so, for he will have to supply an equivalent piece of meat for the one he exchanges. We do not expect him to cause sin without deriving any benefit. If, however, he has a reputation for stealing, his word is not accepted (Maggid Mishneh). Even the servants and maidservants29I.e., Canaanite servants, non-Jews purchased as servants who have undergone a partial conversion process (Hilchot Issurei Bi'ah 12:11). of the Jews are trusted with regard to such a matter. A gentile, by contrast, is not [trusted], for we fear that he will exchange [the meat].30For a gentile is never trusted in any matters involving Jewish observance. When one desires to send food that involves prohibitions with a gentile, it is necessary to take precautions as stated in Chapter 13, Halachot 8-10.

הלכה יא
עֶשֶׂר חֲנֻיּוֹת תֵּשַׁע מוֹכְרוֹת בְּשַׂר שְׁחוּטָה וְאַחַת מוֹכֶרֶת נְבֵלוֹת וְלָקַח בָּשָׂר מֵאַחַת מֵהֶן וְאֵינוֹ יוֹדֵעַ מֵאֵיזֶה מֵהֶן לָקַח הֲרֵי זֶה אָסוּר שֶׁכָּל קָבוּעַ כְּמֶחֱצָה עַל מֶחֱצָה דָּמִי. אֲבָל בָּשָׂר הַנִּמְצָא מֻשְׁלָךְ בַּשּׁוּק הַלֵּךְ אַחַר הָרֹב דְּכָל דְּפָרִישׁ מֵרֻבָּא פָּרִישׁ. אִם הָיוּ רֹב הַמּוֹכְרִים עַכּוּ''ם אָסוּר. וְאִם הָיוּ רֹב הַמּוֹכְרִים יִשְׂרָאֵל מֻתָּר:
כסף משנה
11.
[The following rule applies when there are] ten stores, nine sell kosher meat and one sells nevelot.31I.e., even if the proportions are heavily weighted in favor of the conclusion that the meat is kosher, we accept the possibility that it is non-kosher. If one purchased meat from one of these stores and did not know which one he purchased from, [the meat] is forbidden. [The rationale is that] whenever [the presence of a forbidden entity] is firmly established, the situation is considered as half and half.32This is a general principle applying in many other contexts as well, e.g., Hilchot Chametz UMatzah 2:10, Hilchot Issurei Bi'ah 18:15.
If, however, meat is found cast away in the street,33The Hagahot Maimoniot explains that this law applies only when the meat is discovered in the public domain. If a person is seen taking meat from a store, but it is not known which store he took it from, the previous law applies. [it is judged] according to the majority. For [we follow the assumption:] Anything that was separated, separated from the majority.34This also is a frequently employed Talmudic principle. If the majority of sellers were gentile, [the meat] is forbidden. If the majority were Jewish, it is permitted.

הלכה יב
וְכֵן בָּשָׂר הַנִּמְצָא בְּיַד עַכּוּ''ם וְאֵינוֹ יָדוּעַ מִמִּי לָקַח אִם הָיוּ מוֹכְרֵי הַבָּשָׂר יִשְׂרָאֵל מֻתָּר. זֶה הוּא דִּין תּוֹרָה. וּכְבָר אָסְרוּ חֲכָמִים כָּל הַבָּשָׂר הַנִּמְצָא בֵּין בַּשּׁוּק בֵּין בְּיַד עַכּוּ''ם אַף עַל פִּי שֶׁכָּל הַשּׁוֹחֲטִין וְכָל הַמּוֹכְרִין יִשְׂרָאֵל. וְלֹא עוֹד אֶלָּא הַלּוֹקֵחַ בָּשָׂר וְהִנִּיחוֹ בְּבֵיתוֹ וְנֶעֱלַם מִן הָעַיִן אָסוּר אֶלָּא אִם כֵּן הָיָה לוֹ בּוֹ סִימָן אוֹ שֶׁהָיָה לוֹ בּוֹ טְבִיעַת עַיִן וְהוּא מַכִּירוֹ וַדַּאי שֶׁהוּא זֶה אוֹ שֶׁהָיָה צָרוּר וְחָתוּם:
כסף משנה
12.
Similarly, when meat is found in the hand of a gentile and it is not known from where he purchased it, if [the majority of] the sellers of meat were Jewish, it is permitted.
This reflects the ruling according to Scriptural Law. [Nevertheless,] our Sages have already forbidden any meat found in the marketplace or in the possession of a gentile35As mentioned by the Maggid Mishneh, there are Rishonim who permit meat found in the possession of a gentile when the majority of the sellers are Jewish, maintaining that this is evident from Chullin 95a. The Shulchan Aruch (Yoreh De'ah 63:1, however, quotes the Rambam's view. even though all the slaughterers and all the sellers are Jewish. Moreover, even if one purchased meat, left it in his house, and it disappeared from one's sight, it is forbidden36According to the literal meaning of the Rambam's words, if meat was placed in the freezer, it would be forbidden. The Shulchan Aruch (Yoreh De'ah 63:2) cites, however, the opinion of Rashbam which permits the meat if it is found in the same place that it was placed. The Rama writes that it is customary to follow this view. unless it had a distinguishing mark, he was familiar with it and could recognize it definitely as [the piece of meat lost],37The Maggid Mishneh states that if a person has a reputation for upright conduct, his word is accepted in this concept even if he is not a Torah scholar. Note the contrast to Hilchot Gezeilah V'Aveidah 14:12 which accepts only the word of a Torah scholar if one claims to recognize a lost object, but cannot identify it with distinctive marks. or it was bound and sealed.

הלכה יג
תָּלָה כְּלִי מָלֵא חֲתִיכוֹת בָּשָׂר וְנִשְׁבַּר הַכְּלִי וְנָפְלוּ הַחֲתִיכוֹת לָאָרֶץ וּבָא וּמָצָא חֲתִיכוֹת וְאֵין לוֹ בָּהֶן סִימָן וְלֹא טְבִיעַת עַיִן הֲרֵי זֶה אָסוּר שֶׁיֵּשׁ לוֹמַר אוֹתוֹ בָּשָׂר שֶׁהָיָה בַּכְּלִי גְּרָרַתּוּ חַיָּה אוֹ שֶׁרֶץ וְזֶה בָּשָׂר אַחֵר הוּא:
כסף משנה
13.
[The following rule applies when] one hung a container filled with pieces of meat, the container broke, and the pieces fell to the earth.38If, however, he found it as he left it, it is certainly permitted (Maggid Mishneh). If there is no distinguishing mark [on the meat] and he was not able to recognize it, it is forbidden. [The rationale is that] it is possible to say that the meat that was in the container was dragged away by a wild beast or creeping animal and this is other meat.

הלכה יד
גִּיד הַנָּשֶׁה מֻתָּר בַּהֲנָאָה. לְפִיכָךְ מֻתָּר לְאָדָם לִשְׁלֹחַ לְעַכּוּ''ם יָרֵךְ שֶׁגִּיד הַנָּשֶׁה בְּתוֹכָהּ. וְנוֹתֵן לוֹ הַיָּרֵךְ שְׁלֵמָה בִּפְנֵי יִשְׂרָאֵל. וְאֵין חוֹשְׁשִׁין שֶׁמָּא יֹאכַל מִמֶּנָּה יִשְׂרָאֵל זֶה קֹדֶם שֶׁיִּנָּטֵל הַגִּיד שֶׁהֲרֵי מְקוֹמוֹ נִכָּר. לְפִיכָךְ אִם הָיְתָה הַיָּרֵךְ חֲתוּכָה לֹא יִתְּנֶנָּה לְעַכּוּ''ם בִּפְנֵי יִשְׂרָאֵל עַד שֶׁיִּטּל הַגִּיד שֶׁמָּא יֹאכַל מִמֶּנָּה יִשְׂרָאֵל:
כסף משנה
14.
It is permitted to derive benefit from a gid hanesheh.39The Maggid Mishneh notes that according to Pesachim 22a, it would appear that the authorities who maintain that the gid hanesheh has no flavor also maintain that it is forbidden to benefit from it. Now the Rambam follow the perspective that the gid hanesheh has no flavor (see Halachah 5). Hence his position here is somewhat difficult. The Maggid Mishneh explains, however, that the two positions are not necessary interrelated and both rulings of the Rambam can be upheld. Therefore it is permissible for a person to send a thigh which contains a gid hanesheh to a gentile.40I.e., because there is no prohibition against receiving benefit from the gid hanesheh, he does not have to remove it before selling the meat. He may give him the entire thigh intact in the presence of a Jew. We do not suspect that [the other] Jew will partake of this meat before the gid is removed, because its place is recognizable.41Since the Jew sees a co-religionist giving the gentile the meat, he will assume that it was ritually slaughtered and that the meat was kosher. [This applies in a place where public announcements are made when an animal is discovered to be trefe (Chullin 93b). Otherwise, the Jew must tell the gentile that the animal is kosher (Shulchan Aruch, Yoreh De'ah 65:11)].
Nevertheless, since the place of the gid hanesheh is recognizable - i.e., it is obvious whether the gid is still in the thigh or has already been removed - he will not partake of the meat until the gid is removed.
Accordingly, if the thigh was cut into pieces, he should not give it to a gentile in the presence of a Jew, lest the other Jew partake of it.42Since the place of the gid hanesheh is not obvious, the other Jew may think that ordinary kosher meat is being given and may partake of it.

הלכה טו
כָּל מָקוֹם שֶׁנֶּאֱמַר בַּתּוֹרָה לֹא תֹאכַל לֹא תֹאכְלוּ לֹא יֹאכְלוּ לֹא יֵאָכֵל אֶחָד אִסּוּר אֲכִילָה וְאֶחָד אִסּוּר הֲנָאָה בְּמַשְׁמָע עַד שֶׁיִּפְרֹט לְךָ הַכָּתוּב כְּדֶרֶךְ שֶׁפֵּרֵט לְךָ בִּנְבֵלָה שֶׁנֶּאֱמַר (דברים יד כא) "לַגֵּר אֲשֶׁר בִּשְׁעָרֶיךָ תִּתְּנֶנָּה וַאֲכָלָהּ" וְכַחֵלֶב שֶׁנֶּאֱמַר בּוֹ (ויקרא ז כד) "יֵעָשֶׂה לְכָל מְלָאכָה". אוֹ עַד שֶׁיִּתְפָּרֵשׁ בַּתּוֹרָה שֶׁבְּעַל פֶּה שֶׁהוּא מֻתָּר בַּהֲנָאָה. כְּגוֹן שְׁקָצִים וּרְמָשִׂים וְדָם וְאֵיבָר מִן הַחַי וְגִיד הַנָּשֶׁה. שֶׁכָּל אֵלּוּ מֻתָּרִין בַּהֲנָאָה מִפִּי הַקַּבָּלָה אַף עַל פִּי שֶׁהֵן אֲסוּרִין בַּאֲכִילָה:
כסף משנה
15.
Wherever the Torah states: "Do not eat," "You shall not eat,"43Both of these commands are in the second person: one singular, one plural. "They shall not eat," or "It shall not be eaten," the intent is that it is forbidden both to partake of or benefit from the forbidden entity44Sometimes the command is stated in an active voice; sometimes, it is passive; sometimes, singular and sometimes plural. The passive form implies that it is forbidden to derive any benefit that could lead to one's eating, e.g., selling it for money that could be used to purchase food. unless:
a) a verse explicitly states otherwise, as it does with regard to a nevelah [Deuteronomy 14:21]: "Give it to the stranger in your gate and he shall partake of it," or with regard to forbidden fat [Leviticus 7:24]: "You may use it for any task"; or
b) the Oral Law states explicitly that it is permitted to benefit from it, as is the case with regarding to teeming animals, swarming animals, blood, a limb from a living animal, and the gid hanesheh. For according to the Oral Tradition, it is permitted to benefit from all these prohibited entities, even though it is forbidden to partake of them.

הלכה טז
כָּל מַאֲכָל שֶׁהוּא אָסוּר בַּהֲנָאָה אִם נֶהֱנָה וְלֹא אָכַל כְּגוֹן שֶׁמָּכַר אוֹ נָתַן לְעַכּוּ''ם אוֹ לִכְלָבִים אֵינוֹ לוֹקֶה. וּמַכִּין אוֹתוֹ מַכַּת מַרְדּוּת וְהַדָּמִים מֻתָּרִין. וְכָל דָּבָר שֶׁאָסוּר בַּאֲכִילָה וּמֻתָּר בַּהֲנָאָה אַף עַל פִּי שֶׁהוּא מֻתָּר בַּהֲנָאָה אָסוּר לַעֲשׂוֹת בּוֹ סְחוֹרָה וּלְכַוֵּן מְלַאכְתּוֹ בִּדְבָרִים אֲסוּרִים חוּץ מִן הַחֵלֶב שֶׁהֲרֵי נֶאֱמַר בּוֹ (ויקרא ז כד) "יֵעָשֶׂה לְכָל מְלָאכָה". לְפִיכָךְ אֵין עוֹשִׂין סְחוֹרָה לֹא בִּנְבֵלוֹת וְלֹא בִּטְרֵפוֹת וְלֹא בִּשְׁקָצִים וְלֹא בִּרְמָשִׂים:
כסף משנה
16.
Whenever it is forbidden to benefit from a substance, if a person derives benefit without partaking of it, e.g., he sold or gave to a gentile or gave it to dogs, he is not liable for lashes.45Rav Moshe HaCohen questions this ruling, stating that if the intent of the Scriptural prohibition is that it is forbidden to benefit from these substances, why is one not liable for lashes for deriving such benefit? The Maggid Mishneh explains that he is not liable, for one is liable for lashes only when he derives benefit from the food in the ordinary manner one derives benefit from food. This includes only eating. Receiving money, by contrast, is not considered as benefiting from food in the ordinary manner. Rav Moshe HaCohen, however, anticipated that attempted resolution and explains that, on the contrary, selling edible food is an ordinary way of deriving benefit. He should, however, be given stripes for rebellious conduct. The money [he received] is permitted.46There is one exception to this: money received in return for a false deity or articles associated with it. That money is itself forbidden (see Chapter 13, Halachah 15; Hilchot Avodat Kochavim 7:19).
Whenever it is forbidden to partake of a substance, but it is permitted to benefit from it, even though it is permitted to benefit from it, it is forbidden do business with such articles or establish oneself in a profession that involves forbidden entities.47I.e., one's livelihood may not revolve around the sale of these forbidden entities or performing work with them (e.g., serving as a chef in a non-kosher restaurant). The rationale for the prohibition is that we fear that a person who has extensive involvement with forbidden substances may come to partake of them (Rashba).
The Maggid Mishneh clarifies that the above applies only with regard to food from forbidden species. One may choose a profession that involves employing a horse or a donkey as a beast of burden.
[There is] an exception, forbidden fat, for concerning it, it is written: "You may use it for any task." For this reason, we do not do business with nevelot, trefot, teeming animals, and swarming animals.

הלכה יז
הַצַּיָּד שֶׁנִּזְדַּמְּנוּ לוֹ חַיָּה אוֹ עוֹף וְדָג טְמֵאִים וְצָדָן אוֹ שֶׁנִּצּוֹדוּ לוֹ טְמֵאִים וּטְהוֹרִים מֻתָּר לְמָכְרָן. אֲבָל לֹא יְכַוֵּן מְלַאכְתּוֹ לִטְמֵאִים. וּמֻתָּר לַעֲשׂוֹת סְחוֹרָה בְּחָלָב שֶׁחֲלָבוֹ עַכּוּ''ם וְאֵין יִשְׂרָאֵל רוֹאֵהוּ וּבִגְבִינוֹת הָעַכּוּ''ם וְכַיּוֹצֵא בָּהֶן:
כסף משנה
17.
When a trapper happens upon a non-kosher wild animal, fowl, or fish, and he snares them or he traps both kosher and non-kosher animals, he may sell them.48He must sell them immediately. He may not raise them until they become large [Rama (Yoreh De'ah 117:4)]. See also Siftei Cohen 117:6 who questions whether the leniency is granted only to a professional trapper or to any person. He may not, however, intend to have his profession concern non-kosher species.
It is, however, permitted to do business with milk that was milked by a gentile without being observed by a Jew, cheeses made by gentiles, and the like.

הלכה יח
זֶה הַכְּלָל כָּל שֶׁאִסּוּרוֹ מִן הַתּוֹרָה אָסוּר לַעֲשׂוֹת בּוֹ סְחוֹרָה וְכָל שֶׁאִסּוּרוֹ מִדִּבְרֵיהֶם מֻתָּר לַעֲשׂוֹת בּוֹ סְחוֹרָה בֵּין בִּסְפֵקוֹ בֵּין בְּוַדָּאוֹ:
כסף משנה
18.
This is the general principle: Whenever a prohibition is forbidden by Scriptural Law, it is forbidden to do business with it. Whenever the prohibition is Rabbinic in origin, it is permitted do business with it, whether we are certain of the existence of the prohibition or it is a matter of question.

קדושה הלכות מאכלות אסורות פרק ח
Kedushah Ma`akhalos Assuros Chapter 8