Halacha

הלכה א
פְּסוּקָה כֵּיצַד. חוּט הַשִּׁדְרָה שֶׁנִּפְסַק הָעוֹר הַחוֹפֶה אֶת הַמֹּחַ טְרֵפָה. וּבִלְבַד שֶׁיִּפָּסֵק רֹב הֶקֵּפוֹ. אֲבָל אִם נִסְדַּק הָעוֹר לְאָרְכּוֹ אוֹ נִקַּב מֻתֶּרֶת. וְכֵן אִם נִשְׁבְּרָה הַשִּׁדְרָה וְלֹא נִפְסַק הַחוּט שֶׁלָּהּ אוֹ שֶׁנִּתְמַעֵךְ הַמֹּחַ שֶׁבְּתוֹךְ הַחוּט וְנִתְנַדְנֵד הוֹאִיל וְעוֹרוֹ קַיָּם הֲרֵי זוֹ מֻתֶּרֶת:
כסף משנה
1.
What is meant by the term pesukah?1Pesukah is also one of the eight categories of trefot mentioned in Chapter 5, Halachah 2. The term literally means "severed." If the skin that covers the marrow2We are using this term to translate the Hebrew term moach. It is a loose term that means the material inside a bone. Chullin 45b states that this marrow is no of significance with regard to the category of pesukah. Therefore the Shulchan Aruch (Yoreh De'ah 32:1) rules that if the skin is severed, even if the marrow is entirely intact, the animal is trefe. of the spinal cord is severed, [the animal] is trefe. [This applies] provided the majority of the circumference [of the skin] is severed. If, however, the skin is split lengthwise or perforated, [the animal] is permitted. Similarly, if the backbone was broken, but the spinal cord was not split or the marrow within the cord was crushed and it would wobble, [the animal] is permitted because its skin is still intact.

הלכה ב
הֻמְרַךְ הַמֹּחַ וְנִשְׁפַּךְ כַּמַּיִם אוֹ כְּדוֹנַג שֶׁנָּמֵס עַד שֶׁיִּמָּצֵא הַחוּט כְּשֶׁמַּעֲמִידוֹ אֵינוֹ עוֹמֵד הֲרֵי זוֹ טְרֵפָה. וְאִם אֵינוֹ יָכוֹל לַעֲמֹד מִפְּנֵי כָּבְדּוֹ הֲרֵי זוֹ סָפֵק:
כסף משנה
2.
If the marrow decomposes and it can be poured like water or like molten wax to the extent that the spinal cord cannot stand when it is lifted up, [the animal] is trefe. If [the reason] it cannot stand is because of its weight, [the animal's] status is doubtful.3And hence, forbidden. This ruling is granted because this question is left unresolved by Chullin 45b. The Kessef Mishneh quotes Rashi who explains that this is speaking about a situation where the spine has become thick and heavy, but has not become soft inside. The question is whether this state results from sickness or not.

הלכה ג
עַד הֵיכָן חוּט הַשִּׁדְרָה. תְּחִלָּתוֹ מִבַּחוּץ לַפּוֹלִין שֶׁבִּתְחִלַּת הָעֹרֶף עַד סוֹף פָּרָשָׁה שְׁנִיָּה שֶׁלֹּא יִשָּׁאֵר אַחֲרֶיהָ אֶלָּא פָּרָשָׁה שְׁלִישִׁית הַסְּמוּכָה לִתְחִלַּת הָאַלְיָה:
כסף משנה
3.
To where does the spinal cord extend? It begins behind the two glands at the beginning of the neck and extends until the second divider.4See the following halachah for a definition of this term. Thus nothing remains after it except the third divider which is close to the beginning of the tail.

הלכה ד
וְשָׁלֹשׁ פָּרָשִׁיּוֹת הֵן וְאֵלּוּ הֵן. שְׁלֹשָׁה עֲצָמוֹת דְּבוּקִין זֶה בָּזֶה לְמַטָּה מֵחֻלְיוֹת שֶׁל שִׁדְרָה. וְחוּט הַשִּׁדְרָה בָּעוֹף עַד בֵּין אֲגַפַּיִים. אֲבָל לְמַטָּה מִמְּקוֹמוֹת אֵלּוּ אֵין מַשְׁגִּיחִין עַל הַחוּט הַנִּמְשָׁךְ לְשָׁם בֵּין שֶׁנִּפְסַק עוֹרוֹ בֵּין שֶׁנִּמְרַךְ הַמֹּחַ:
כסף משנה
4.
There are three dividers. They are three bones that cleave to each other below the vertebrae of the backbone. The spinal cord of a fowl extends to in between the wings.5The Shulchan Aruch (Yoreh De'ah 32:5) interprets this as meaning the place where the wings are attached to the body. The Rama follows the opinion of Tosafot who state that the term refers to the place where the wings lie on the body, a point somewhat lower on the fowl's back. Below these places, we are not concerned with the cord that extends there, even if its skin was severed or its marrow decays.6For these portions are not fundamental for the body's functioning.

הלכה ה
קְרוּעָה כֵּיצַד. בָּשָׂר הַחוֹפֶה אֶת רֹב הַכֶּרֶס וְהוּא הַמָּקוֹם מִן הַבֶּטֶן שֶׁאִם יִקָּרַע יֵצֵא הַכֶּרֶס אִם נִקְרַע בָּשָׂר זֶה טְרֵפָה. אַף עַל פִּי שֶׁלֹּא הִגִּיעַ הַקֶּרַע לַכֶּרֶס עַד שֶׁנִּרְאֵית. אֶלָּא כֵּיוָן שֶׁנִּקְרַע רֹב עֳבִי הַבָּשָׂר הַזֶּה אוֹ נִטַּל טְרֵפָה. וְכַמָּה שִׁעוּר הַקֶּרַע בְּאָרְכּוֹ אֹרֶךְ טֶפַח. וְאִם הָיְתָה בְּהֵמָה קְטַנָּה וְנִקְרַע רֹב אֹרֶךְ הַבָּשָׂר הַחוֹפֶה אֶת הַכֶּרֶס אַף עַל פִּי שֶׁאֵין בְּאֹרֶךְ הַקֶּרַע טֶפַח טְרֵפָה הוֹאִיל וְנִקְרַע רֻבָּהּ:
כסף משנה
5.
What is meant by the term keru'ah?7Keru'ah is also one of the eight categories of trefot mentioned in Chapter 5, Halachah 2. The term literally means "ripped apart." [This concerns] the flesh which covers the majority of [the animal's] belly. If it is ripped open, the belly will [fall] out. If this flesh is ripped open, [the animal] is trefe. [This applies] even if the tear did not reach the belly itself to the extent that it is seen. Instead, since the majority of the thickness of this flesh was ripped open8I.e., but some flesh remained. The animal is deemed trefe, because in such a condition, ultimately, the entire flesh will tear open.
The Kessef Mishneh notes that many others authorities interpret Chullin 50b, the Rambam's source, as implying that if the cut extends over the majority of the animal's belly, the animal is trefe. In his Kessef Mishneh, Rav Yosef Caro quotes the Rashba as explaining that the Rambam does not accept this approach because if so, there would be no difference between the categories of pesukah and keru'ah. The Rashba himself does not require such a distinction and instead, maintains that these categories overlap. In his Shulchan Aruch (Yoreh De'ah 48:3), he quotes the Rambam's view. The Turei Zahav 48:5 and the Siftei Cohen 48:4 mention the other positions.
or removed, [the animal] is trefe.
What is the measure of the tear? It must be a handbreadth long. If the animal was small and the majority of the length9The dissenting perspectives also maintain that the same ruling applies with regard to the majority of the breadth of the belly (Siftei Cohen 48:6). of the flesh covering the belly was torn, it is trefe even though the tear is not a handbreadth long. For the majority [of its length] was torn.

הלכה ו
נִקְדַּר הַבָּשָׂר הַזֶּה בְּעִגּוּל אוֹ בְּאֹרֶךְ אִם הָיָה יָתֵר מִכְּסֶלַע וְהוּא כְּדֵי שֶׁיִּכָּנֵס בּוֹ שָׁלֹשׁ גַּרְעִינֵי תְּמָרָה זוֹ בְּצַד זוֹ בְּדֹחַק הֲרֵי זוֹ טְרֵפָה. שֶׁאִם יִמָּתַח קֶרַע זֶה יַעֲמֹד עַל טֶפַח:
כסף משנה
6.
[The following rules apply if] a circular or oblong portion of this flesh was cut.10The previous halachah was speaking about a slit where the flesh was not necessarily cut away. This halachah speaks about a situation where a portion of flesh was removed (Kessef Mishneh). If it was larger than a sela,11A coin of the Talmudic era with a diameter that is a third of a handbreadth, i.e., 2.6 cm. According to Shiurei Torah. i.e., large enough to fit tightly three date seeds next to each other, [the animal] is trefe. For when this size cut will be extended, it will be a handbreadth in length.12I.e., a sela is a little more than a third of a handbreadth. Hence the circumference of the cut is a handbreadth.

הלכה ז
בְּהֵמָה שֶׁנִּפְשַׁט הָעוֹר שֶׁעָלֶיהָ כֻּלּוֹ בֵּין שֶׁנִּקְרַע בַּיָּד אוֹ בְּחלִי וְנִמְצָא בָּשָׂר בְּלֹא עוֹר הֲרֵי זוֹ טְרֵפָה. וְזוֹ הִיא שֶׁנִּקְרֵאת גְּלוּדָה. וְאִם נִשְׁאַר מִן הָעוֹר רֹחַב סֶלַע עַל פְּנֵי כָּל הַשִּׁדְרָה וְרֹחַב סֶלַע עַל הַטַּבּוּר וְרֹחַב סֶלַע עַל רָאשֵׁי אֵיבָרֶיהָ הֲרֵי זוֹ מֻתֶּרֶת. וְאִם נִטַּל כְּרֹחַב סֶלַע מֵעַל כָּל פְּנֵי הַשִּׁדְרָה אוֹ מֵעַל הַטַּבּוּר אוֹ מֵעַל רָאשֵׁי אֵיבָרֶיהָ וּשְׁאָר כָּל הָעוֹר קַיָּם הֲרֵי זוֹ סָפֵק. וְיֵרָאֶה לִי שֶׁמַּתִּירִין אוֹתָהּ:
כסף משנה
7.
When the skin of an animal was removed from it entirely - whether it was torn off by hand or [decomposed due to] sickness - the animal is trefe. This is called geludah. If a [portion of] skin as wide as a sela remained on the entire backbone, one as wide as a sela remained on the navel, and one as wide as a sela remained on the tips of the limbs, [the animal] is permitted.13Chullin 55b mentions a tradition that maintains that if an animal's entire skin is removed except for a portion the size of a sela, the animal is acceptable. [For from this portion, the entire skin will be regenerated (Rashi).] The Talmud continues mentioning three views, concerning where the skin must remain. Since the matter remains unresolved and we do not know which of these views should be followed, the Rambam rules that all of the different views must be respected and a portion of skin the size of a sela must remain in each place (Kessef Mishneh).
(Significantly, in his Commentary on the Mishnah (Chullin 3:2), the Rambam mentions only the view that requires skin on the backbone and not the other opinions.)

If [a portion] as wide as a sela was removed from the entire backbone, from the navel, or from the tips of the limbs, but the remainder of the skin remained intact, there is a doubt [concerning the ruling].14This question is left unresolved by Chullin, loc. cit. Hence there is a doubt concerning the ruling. It appears to me that we permit [the animal].15Many authorities question the Rambam's ruling. Seemingly, if the question was left unresolved by the Talmud, on what basis does the Rambam permit it?
In his Kessef Mishneh, Rav Yosef Caro offers two explanations for the Rambam's ruling:
a) As the Rambam states in Chapter 5, Halachah 3, since all the categories of trefot aside from a derusah are not mentioned explicitly in the Torah, we rule leniently concerning doubts.
b) Since the skin was removed from only one of three places mentioned, there is a multiple doubt (sefek s'feikah) involved. Perhaps the place from which the skin was removed was in fact not the vital area (for the halachah could follow one of the other views). Even if it was the vital area, perhaps the fact that the skin on the remainder of the body is intact is enough for the animal to be permitted.
In his Shulchan Aruch (Yoreh De'ah 59:1), Rav Yosef Caro quotes the Rambam's ruling. The Siftei Cohen 59:2 mentions the opinions that differ with the Rambam. The Rama adds that if the skin is removed from all three places, the animal is trefe.

הלכה ח
נְפוּלָה כֵּיצַד. הֲרֵי שֶׁנָּפְלָה הַבְּהֵמָה מִמָּקוֹם גָּבוֹהַּ שֶׁגָּבְהוֹ עֲשָׂרָה טְפָחִים אוֹ יֶתֶר וְנִתְרַסֵּק אֵיבָר מֵאֵיבָרֶיהָ הֲרֵי זוֹ טְרֵפָה. וְכֵיצַד הוּא הָרִסּוּק. שֶׁיִּתְרוֹצֵץ הָאֵיבָר וְיֶחֱלֶה מֵחֲמַת הַנְּפִילָה עַד שֶׁתִּפָּסֵד צוּרָתוֹ וְתָאֳרוֹ. אַף עַל פִּי שֶׁלֹּא נִקַּב וְלֹא נִסְדַּק וְלֹא נִשְׁבַּר הֲרֵי זוֹ טְרֵפָה. וְכֵן אִם הִכָּה אוֹתָהּ בְּאֶבֶן אוֹ בְּמַטֶּה וְרִצֵּץ אֵיבָר מֵאֵיבָרֶיהָ טְרֵפָה. בְּאֵי זֶה אֵיבָרִים אָמְרוּ בְּאֵיבָרִים שֶׁבַּחֲלַל הַגּוּף:
כסף משנה
8.
What is meant by the term nefulah?16Nefulah is also one of the eight categories of trefot mentioned in Chapter 5, Halachah 2. The term literally means "one which fell." When an animal fell from a high place - at least ten handbreadths high17In his Kessef Mishneh, Rav Yosef Caro quotes Chullin 50b which states that this refers to a height of four handbreadths above the ground, for there are six handbreadths from the bottom of an animal's belly until the ground. He also cites this view in his Shulchan Aruch (Yoreh De'ah 58:1).
Moreover, in both those sources, Rav Yosef Caro also quotes views that state that this law applies only when the animal fell on its own or knew that it was being pushed by others. If, however, it was pushed suddenly by others, it is considered trefe even if it fell from a lesser height.
- and one of its organs was crushed, it is trefe.
To what extent must it be crushed? It must be smashed and become ailing because of the fall to the extent that its form and appearance have been destroyed. Even though [the organ] is not perforated, cracked, or broken, [the animal] is trefe. Similarly, if one struck it with a stone or a staff and crushed one of its organs, it is trefe.18In this instance, the distance of ten handbreadths is not significant. Instead, if it was thrown with enough force to cause mortal damage, it can cause the animal to be rendered trefe.
To which organs are we referring? To those in the body's inner cavity.19Therefore all of those organs must be inspected (Chullin 51a). The Ra'avad states that every organ that would render the animal trefe if crushed must be inspected.
The Rama (Yoreh De'ah 58:6) writes that in the present era, we are not knowledgeable with regard to conducting these examinations and an animal that falls should be permitted only if it walks, as stated in the next halachah.

הלכה ט
בְּהֵמָה שֶׁנָּפְלָה מִן הַגַּג אִם הָלְכָה אֵין חוֹשְׁשִׁין לָהּ. וְאִם עָמְדָה וְלֹא הָלְכָה חוֹשְׁשִׁין לָהּ. קָפְצָה מֵחֲמַת עַצְמָהּ אֵין חוֹשְׁשִׁין לָהּ. הִנִּיחָהּ לְמַעְלָה וּמְצָאָהּ לְמַטָּה אֵין חוֹשְׁשִׁין לָהּ שֶׁמָּא נָפְלָה:
כסף משנה
9.
If an animal walks after falling from a roof, we do not suspect [that it became trefe].20Walking is adequate proof that the animal was not injured by the fall to the extent that it would no longer survive. Since it walks, we assume that it is healthy and do not require an internal examination, as stated in Halachah 17. The Kessef Mishneh emphasizes that this applies only when the animal stood up on its own and then walked. If it was lifted up by others, we harbor suspicions. Similarly, he quotes authorities who maintain that it must walk in an ordinary manner. If it limps as it proceeds, an inspection is required. See Rama (Yoreh De'ah 58:6).
In his Shulchan Aruch (Yoreh De'ah 58:5), Rav Yosef Caro quotes the opinion of the Rashba who writes that even if an obvious change was seen in its organs, as long as it was able to stand and walk, we do not suspect that it has become trefe.
If it stood, but did not walk, we harbor such suspicions.21And require an inspection. If it jumped [from the roof] on its own [initiative], we do not harbor suspicions.22For we assume that it prepared itself and jumped in a manner that would not cause injury. The Shulchan Aruch (Yoreh De'ah 58:11) states that this applies even if the animal is not able to walk afterwards. If [a person] left his animal on the roof and found it on the ground, we do not suspect that it fell.23We assume that it jumped intentionally, as explained above.

הלכה י
זְכָרִים הַמְנַגְּחִין זֶה אֶת זֶה אֵין חוֹשְׁשִׁין לָהֶן. נָפְלוּ לָאָרֶץ חוֹשְׁשִׁין לָהֶן. וְכֵן בְּהֵמָה שֶׁהָיְתָה מְגָרֶרֶת רַגְלֶיהָ אֵין חוֹשְׁשִׁין לָהּ שֶׁמָּא נִתְרַסְּקוּ אֵיבָרֶיהָ אוֹ שֶׁמָּא נִפְסַק הַחוּט שֶׁל שִׁדְרָה:
כסף משנה
10.
When bulls butt each other, we do not harbor suspicions.24We do not assume that their inner organs were crushed, because this is ordinary behavior. If one falls to the ground, we do harbor suspicions.25Chullin 51a states that we harbor suspicions, not because of the butting, but because the animal fell and we fear that it was injured by the fall. Similarly, [if we see] an animal dragging its feet, we do not suspect that its organs were crushed or that its backbone was severed.26I.e., if we do not know that it fell.

הלכה יא
גַּנָּבִים שֶׁגּוֹנְבִין הַטְּלָאִים וּמַשְׁלִיכִין אוֹתָן לַאֲחוֹרֵי הַדִּיר אֵין חוֹשְׁשִׁין לָהֶן מִשּׁוּם רִסּוּק אֵיבָרִים. מִפְּנֵי שֶׁאֵין מַשְׁלִיכִין אוֹתָן אֶלָּא בְּכַוָּנָה שֶׁלֹּא יִשְׁתַּבְּרוּ. וְאִם הֶחֱזִירוּם וְהִשְׁלִיכוּם לַדִּיר מֵחֲמַת יִרְאָה חוֹשְׁשִׁין לָהֶן. מֵחֲמַת תְּשׁוּבָה אֵין חוֹשְׁשִׁין לָהֶן. מִפְּנֵי שֶׁמִּתְכַּוֵּן לְהַחֲזִירָם שְׁלֵמִים וְיִזָּהֲרוּ בְּהַשְׁלָכָתָן:
כסף משנה
11.
When thieves steal lambs and throw them outside the corral, we do not suspect that their organs were crushed, because they throw them only with the intent that they will not be broken.27Otherwise, the stolen animal will not be of any benefit to them. If they returned them and threw them back to the corral because of fear,28I.e., the fear of being caught. we suspect that they [may have become trefe].29For the thieves will not show any care for the animal while throwing it back into the corral. If they returned them out of a desire to repent, we do not harbor suspicions about [the lambs], because [the thieves] have the intent of returning them intact and therefore they will be careful when throwing them back.

הלכה יב
שׁוֹר שֶׁהִרְבִּיצוּהוּ לִשְׁחִיטָה אַף עַל פִּי שֶׁנָּפַל נְפִילָה גְּדוֹלָה שֶׁיֵּשׁ לָהּ קוֹל בְּעֵת שֶׁמַּפִּילִין אוֹתוֹ אֵין חוֹשְׁשִׁין לוֹ מִפְּנֵי שֶׁנּוֹעֵץ צִפָּרְנָיו וּמִתְחַזֵּק עַד שֶׁמַּגִּיעַ לָאָרֶץ:
כסף משנה
12.
When an ox was forced to lie down for slaughter, we do not suspect [that its internal organs were crushed]. [This applies] even if it fell considerably to the extent that it made a great noise30Rashi (Chullin, loc. cit.) interprets this as meaning that the ox bellowed, but this does not appear to be the Rambam's understanding. when it fell. [The rationale is that] it implants its hooves into it and strengthens itself until it falls to the ground.31I.e., it is aware that they are trying to push it to the ground and it fights against them, thus lessening the impact of its fall. The Rama (Yoreh De'ah 58:10) writes that if the ox's feet are tied when it is pushed to the ground, we do suspect that it may have become trefe. For when its feet are tied, it cannot control its fall.

הלכה יג
הִכָּה הַבְּהֵמָה עַל רֹאשָׁהּ וְהָלְכָה לָהּ הַמַּכָּה כְּלַפֵּי זְנָבָהּ אוֹ עַל זְנָבָהּ וְהָלְכָה לָהּ כְּלַפֵּי רֹאשָׁהּ וַאֲפִלּוּ הִכָּה אוֹתָהּ בַּמַּטֶּה עַל כָּל הַשִּׁדְרָה אֵין חוֹשְׁשִׁין לָהּ. וְאִם יֵשׁ בַּמַּטֶּה חֻלְיוֹת חֻלְיוֹת חוֹשְׁשִׁין לָהּ. וְאִם הִגִּיעַ רֹאשׁ הַמַּטֶּה לְמִקְצָת הַשִּׁדְרָה חוֹשְׁשִׁין לָהּ. וְכֵן אִם הִכָּה לְרֹחַב הַשִּׁדְרָה חוֹשְׁשִׁין לָהּ:
כסף משנה
13.
If one struck an animal on its head and the blow extended toward its tail or [one hit it] on its tail and the blow extended toward its head - even if one struck it on the entire backbone - we do not suspect [that it became trefe]. If the staff had bulges at different points, we harbor suspicions [concerning the animal].32For the blows dealt by the bulges will be far more severe. Hence the backbone must be inspected to see that it is intact. See Turei Zahav 32:4. If the head of the staff reached a portion of the backbone,33In the previous clauses, the head of the staff did not carry with the brunt of the blow, because the lower portion of the staff struck the animal's body first. Here we are speaking about a situation where the first and primary focus of the blow is delivered to the backbone by the top of the staff. This is a far more dangerous situation. we harbor suspicions. Similarly, we harbor suspicions if he struck the animal across the breadth of the backbone.34For the entire blow is focused on one point of the spinal cord.

הלכה יד
עוֹף שֶׁנֶּחְבַּט עַל דָּבָר קָשֶׁה כְּגוֹן כְּרִי שֶׁל חִטִּים אוֹ קֻפָּה שֶׁל שְׁקֵדִים וְכַיּוֹצֵא בָּהֶן חוֹשְׁשִׁין לְרִסּוּק אֵיבָרִים. וְאִם נֶחְבַּט עַל דָּבָר רַךְ כְּגוֹן כְּסוּת כְּפוּלָה וְהַתֶּבֶן וְהָאֵפֶר וְכַיּוֹצֵא בָּהֶן אֵין חוֹשְׁשִׁין לוֹ:
כסף משנה
14.
When a fowl is knocked against a firm article,35Or conversely, if a firm article like a stone falls upon it [Rama (Yoreh De'ah 58:2)]. e.g., a heap of grain, a mound of almonds, or the like, we suspect that its organs may have been crushed. If, by contrast, it is knocked against something soft, e.g., a folded garment, straw,36I.e., a mound of loose straw. Straw that has been bundled, by contrast, is considered as a firm article (Chullin 51b)., ashes, or the like, we do not harbor such suspicions.

הלכה טו
נִדְבְּקוּ כְּנָפָיו בְּדֶבֶק בִּשְׁעַת צִידָה וְנִתְחַבֵּט. אִם בְּכָנָף אַחַת נֶאֱחַז אֵין חוֹשְׁשִׁין לוֹ. וְאִם נֶאֱחַז בִּשְׁתֵּי כְּנָפָיו וְנִתְחַבֵּט בְּגוּפוֹ חוֹשְׁשִׁין לוֹ:
כסף משנה
15.
[The following rules apply when a fowl's] wings became stuck with glue37One of the techniques with which hunters would trap wild fowl would be to set traps for them which would glue their wings to boards or other articles that prevented them from flying. when it was being captured and it received a blow. If only one wing became stuck, we do not suspect [that it became trefe].38For by flapping the other wing, it will slow its fall and lessen the impact. If both of its wings became stuck and it receive a blow on its body, we harbor suspicions.39For there is nothing to soften the blow.

הלכה טז
נֶחְבַּט עַל פְּנֵי הַמַּיִם אִם שָׁט מְלֹא קוֹמָתוֹ מִמַּטָּה לְמַעְלָה לְעֵמַּת הַמַּיִם אֵין חוֹשְׁשִׁין לוֹ. אֲבָל אִם שָׁט מִמַּעְלָה לְמַטָּה עִם הִלּוּךְ הַמַּיִם חוֹשְׁשִׁין לוֹ שֶׁמָּא הַמַּיִם הֵם הַמּוֹלִיכִין אוֹתוֹ. וְאִם קָדַם לְתֶבֶן אוֹ קַשׁ שֶׁמְּהַלְּכִין עַל גַּבֵּי הַמַּיִם הֲרֵי זוֹ שָׁט מֵחֲמַת עַצְמוֹ וְאֵין חוֹשְׁשִׁין לוֹ:
כסף משנה
16.
[The following rules apply if] it is knocked against water.40It was snared and fell unto a river. If it swam for its full height upriver, against the current, we do not suspect [that it became trefe].41For this exertion indicates that the animal is fundamentally healthy. It is equivalent to - or exceeds - the walking mentioned in Halachah 9. If, however, it swims downriver, with the current, we harbor suspicions, for perhaps the water is carrying it.42In a still body of water that has no current, any swimming is a sign of health (see Siftei Cohen 58:10). If it advances toward straw or hay that is floating on the river, it is swimming on its own power and we do not harbor suspicions.

הלכה יז
כָּל מָקוֹם שֶׁאָמַרְנוּ אֵין חוֹשְׁשִׁין לָהּ מֻתָּר לִשְׁחֹט מִיָּד. וְאֵינוֹ צָרִיךְ לִבְדֹּק שֶׁמָּא נִתְרַסֵּק אֵיבָר. וְכָל מָקוֹם שֶׁאָמַרְנוּ חוֹשְׁשִׁין לָהּ אִם שְׁחָטָהּ צָרִיךְ לִבְדֹּק כְּנֶגֶד כָּל הֶחָלָל כֻּלּוֹ מִקָּדְקֹד הָרֹאשׁ עַד הַיָּרֵךְ. אִם מָצָא בָּהּ טְרֵפָה מִן הַטְּרֵפוֹת שֶׁמָּנִינוּ אוֹ שֶׁנִּתְרַסֵּק אֵיבָר מִן הָאֵיבָרִים שֶׁבִּפְנִים וְנִפְסְדָה צוּרָתוֹ הֲרֵי זוֹ טְרֵפָה. אֲפִלּוּ נִתְרַסֵּק אֵיבָר מִן הָאֵיבָרִים שֶׁאִם נִטְּלוּ כְּשֵׁרָה כְּגוֹן טְחוֹל וּכְלָיוֹת הֲרֵי זוֹ טְרֵפָה חוּץ מִבֵּית הָרֶחֶם שֶׁאִם נִתְרַסֵּק הֲרֵי זוֹ מֻתֶּרֶת:
כסף משנה
17.
In all situations where we said: "We do not harbor suspicions," it is permitted to slaughter [the animal] immediately and it is not necessary to check whether an organ was crushed. In all situations where we said: "We harbor suspicions," if one slaughters the animal, one must check its entire internal category from the head to the hind-thigh.43The Shulchan Aruch (Yoreh De'ah 58:3) quotes the Rambam's ruling. As mentioned above, the Rama (Yoreh De'ah 58:6) states that in the present age, we are not knowledgeable with regard to conducting these examinations and an animal is permitted only if it walks after falling or receiving a blow. If any of the factors that render an animal trefe mentioned above were discovered or one of the inner organs was crushed to the extent that its form was destroyed, [the animal] is trefe. Even if one of the organs whose removal does not render the animal trefe,44The Ra'avad differs and maintains that there is an unresolved doubt with regard to the ruling in this instance. As mentioned, the Shulchan Aruch follows the Rambam's position.
The Kessef Mishneh explains the Rambam's ruling as follows: Since Chullin 51a states that if the uterus is crushed, it is not significant, we conclude that the crushing of all other internal organs is significant. Otherwise, it would not be necessary to single out the uterus. Moreover, he explains that crushing an organ can be more painful and more injurious to an animal than removing it.
e.g., the spleen or the kidneys, is crushed, [the animal] is trefe. [There is] an exception, the uterus; if it is crushed, the animal is permitted.

הלכה יח
וְהַסִּימָנִין אֵינָן צְרִיכִין בְּדִיקָה בְּכָאן שֶׁאֵין הַנְּפִילָה מְמַעֶכֶת אוֹתָן:
כסף משנה
18.
[The gullet and the windpipe] do not require examination in these situations, for a fall will not crush them.

הלכה יט
נָפְלָה מִן הַגַּג וְלֹא עָמְדָה אָסוּר לִשְׁחֹט אוֹתָהּ עַד שֶׁתִּשְׁהֵא מֵעֵת לְעֵת. וְאִם שָׁחַט בְּתוֹךְ זְמַן זֶה הֲרֵי זוֹ טְרֵפָה. וּכְשֶׁשּׁוֹחֵט אוֹתָהּ אַחַר מֵעֵת לְעֵת צְרִיכָה בְּדִיקָה כְּמוֹ שֶׁבֵּאַרְנוּ:
כסף משנה
19.
When an animal fell from a roof and did not stand [afterwards],45I.e., if it stands - even if it does not walk - it can be slaughtered immediately and deemed acceptable through an examination, as above. it is forbidden to slaughter it until one waits an entire day.46For sometimes the effects of a fall are not immediately evident. It is possible that an animal would be inspected and no difficulty found, but in truth, the effects of the fall would be enough to kill it. To reduce the possibility of such an occurrence, Chullin 51b requires waiting an entire day before slaughtering the animal. See Kessef Mishneh. If one slaughtered it during this time, it is trefe. When one slaughters it after a day has passed, an examination is required, as we explained.47See Halachah 17.

הלכה כ
וְכֵן מִי שֶׁדָּרַס בְּרַגְלוֹ עַל הָעוֹף אוֹ שֶׁדְּרָסַתּוּ בְּהֵמָה אוֹ שֶׁטְּרָפוֹ לַכֹּתֶל וַהֲרֵי הוּא מְפַרְכֵּס מַשְׁהִין אוֹתוֹ מֵעֵת לְעֵת וְאַחַר כָּךְ שׁוֹחֲטִין אוֹתוֹ וּבוֹדְקִין אוֹתוֹ כְּדֶרֶךְ שֶׁבֵּאַרְנוּ:
כסף משנה
20.
Similarly, if a person treaded on a fowl48Chullin 56a describes such a situation with regard to an animal. The Rambam speaks of a fowl instead, for this is a more commonplace possibility. with his feet, an animal trampled it, or it was crushed against a wall and it is in its death throes, we leave it alive for a day. Afterwards, we slaughter it and examine it,49Lest its organs have been crushed. as we stated.

הלכה כא
סִימָנִים שֶׁנִּדַּלְדְּלוּ רֻבָּן טְרֵפָה וַאֲפִלּוּ שֶׁלֹּא מֵחֲמַת נְפִילָה. וְכֵן אִם נִתְקַפְּלוּ שֶׁהֲרֵי אֵינָן רְאוּיִין לִשְׁחִיטָה. אֲבָל אִם נִתְפָּרֵק רֹב תַּרְבַּץ הַוֵּשֶׁט מִן הַלֶּחִי הֲרֵי זוֹ מֻתֶּרֶת שֶׁאֵין הַתַּרְבַּץ רָאוּי לִשְׁחִיטָה כְּמוֹ שֶׁבֵּאַרְנוּ:
כסף משנה
21.
When the majority of [the windpipe and the gullet were separated50This addition is made on the basis of the Kessef Mishneh and the Shulchan Aruch (Yoreh De'ah 33:10). and] hang loosely, [the animal] is trefe. [This applies] even if [this condition occurs] due to reasons other than a fall.51Nevertheless, the Rambam mentions this condition here in connection with an animal that has fallen, because this is the most frequent situation in which this condition will occur. Similarly, if they became folded over,52They came loose from the place where they are attached within the throat area. See Chapter 3, Halachah 14, and Chapter 8, Halachah 23. [the animal is unacceptable,] because they are no longer fit for ritual slaughter.53The Kessef Mishneh states that the Rambam rules that the animal is unacceptable, not because it would die because of this condition, but because it is impossible to slaughter it correctly. If, by contrast, [even though] the majority54If, however, the entire throat became loose from the jaw, the animal is trefe. For the gullet and the windpipe themselves, however, must remain taut and this is impossible if the entire throat has become loose (Kessef Mishneh). of the throat55I.e., the area referred to by the halachic term "the entrance to the gullet." was set loose from the jaw-bone, [the animal] is permitted, for the throat area is not fit for ritual slaughter, as we explained.56Chapter 1, Halachah 6.

קדושה הלכות שחיטה פרק ט
Kedushah Shechitah Chapter 9