יורה דעה כ״אYoreh De'ah 21

Se’if 1א׳

כַּמָּה הוּא שִׁעוּר הַשְּׁחִיטָה שֶׁל הַקָּנֶה וְהַוֵּשֶׁט; הַשְּׁחִיטָה הַמְּעֻלָּה, שֶׁיֵּחָתְּכוּ שְׁנֵיהֶם בֵּין בַּבְּהֵמָה וּבֵין בָּעוֹף, וְלָזֶה יִתְכַּוֵּן הַשּׁוֹחֵט; וְאִם שָׁחַט רֹב אֶחָד מֵהֶם בָּעוֹף, וְרֹב שְׁנַיִם בַּבְּהֵמָה וּבַחַיָּה, שְׁחִיטָתוֹ כְּשֵׁרָה, וּבִלְבַד כְּשֶׁיִּמְדְּדוּ אוֹתוֹ יִמְצְאוּ שֶׁהַנִּשְׁחָט הוּא רֹב; וְכֵיוָן שֶׁיִּמְצְאוּ שֶׁהַנִּשְׁחָט יוֹתֵר מֵחֵצִי, אֲפִלּוּ כְּחוּט הַשַּׂעֲרָה, דַּיּוֹ.

How much is the measure of the slaughter of the windpipe and the gullet? The choicest slaughter is that both of them be cut, whether in an animal or in a bird, and to this the slaughterer should direct his intention. And if he slaughtered the greater part of one of them in a bird, and the greater part of two in an animal and in a wild beast, his slaughter is valid — provided that when they measure it they find that what was slaughtered is the greater part; and once they find that what was slaughtered is more than half, even as a hair's breadth, it suffices.

Se’if 2ב׳

אִם שָׁחַט בִּבְהֵמָה הָאֶחָד כֻּלּוֹ וַחֲצִי הַשֵּׁנִי, וּבְעוֹף שְׁנֵי חֲצָאֵי סִימָנִים, פְּסוּלָה.

If in an animal he slaughtered the one entirely and half of the second, and in a bird two halves of the simanim — the windpipe and the gullet, which the slaughter must sever — it is invalid.

Se’if 3ג׳

לֹא שָׁחַט רֹב הַסִימָן בְּמָקוֹם אֶחָד, כְּגוֹן שֶׁהִתְחִיל לִשְׁחֹט וְנִתְהַפֵּךְ הַסִימָן וּגְמָרָהּ שָׁם, וּבֵין שְׁנֵיהֶם רֹב, כְּשֵׁרָה בֵּין בִּקְנֵה בֵּין בַּוֵּשֶׁט; לֹא מִבַּעְיָא אִם שְׁנֵי הַחֲתָכִים שָׁוִים בְּהֶקֵּף אֶחָד, אֶלָּא אֲפִלּוּ הָאֶחָד לְצַד הָרֹאשׁ וְהַשֵּׁנִי לְצַד מַטָּה, כָּשֵׁר, בֵּין אִם אָדָם אֶחָד שָׁחַט כָּךְ בִּשְׁנַיִם אוֹ בְּג' מְקוֹמוֹת, בֵּין שֶׁשָּׁחֲטוּ שְׁנַיִם בִּשְׁנֵי סַכִּינִים; אֲבָל אִם הַכֹּל בְּצַד אֶחָד, כְּגוֹן שֶׁלְּאַחַר שֶׁהִתְחִיל לִשְׁחֹט מְעַט הִנִּיחַ זֶה הַמָּקוֹם, וְשָׁחַט לְמַטָּה אוֹ לְמַעְלָה מִמֶּנּוּ בְּאוֹתוֹ צַד, צָרִיךְ שֶׁיְּהֵא הָרֹב בְּמָקוֹם אֶחָד, וּכְשֶׁיֵּשׁ רֹב, אֲפִלּוּ בַּמָּקוֹם הַשֵּׁנִי, כָּשֵׁר, אַף עַל פִּי שֶׁאֵין הַשְּׁחִיטָה מְפֹרַעַת. (פי' גְּלוּיָה וְנִכֶּרֶת).

If he did not slaughter the greater part of the siman in one place — as where he began to slaughter, and the siman turned about, and he finished it there, and between the two of them there is the greater part — it is valid, whether in the windpipe or in the gullet. It need not be said where the two cuts are level in one circumference; but even where the one is toward the head and the second toward below, it is valid, whether one man slaughtered so in two or in three places, or two men slaughtered with two knives. But if the whole of it is on one side — as where, after he had begun to slaughter a little, he left that place and slaughtered below it or above it on that same side — the greater part must be in one place; and when there is the greater part, even in the second place, it is valid, even though the slaughter is not laid open. (that is, revealed and recognisable.)