Yoreh Deah Siman 24 Seif 6

 

ו כְּשֶׁאָדָם שׁוֹחֵט עוֹף וְאוֹחֵז בַּסִימָנִים בִּשְׁתֵּי אֶצְבְּעוֹתָיו צָרִיךְ שֶׁיֶּאֱחֹז אוֹתָם יָפֶה, שֶׁאִם אֵינוֹ אוֹחֵז אוֹתָם בְּטוֹב, פְּעָמִים שֶׁיִּהְיוּ נִשְׁמָטִין לְכָאן וּלְכָאן, וְלֹא יָכוֹל לְשָׁחֲטָן עַל יְדֵי הוֹלָכָה, וּבָא לִידֵי דְּרָסָה.  וַאֲפִלּוּ לֹא עָשָׂה דְּרָסָה אֶלָּא בְּמַשֶּׁהוּ מִן הַוֵּשֶׁט, פְּסוּלָה.

Seif 6

 

When a person slaughters a fowl and holds the signs between two fingers, he needs to hold them well and if he does not hold them well sometimes they will loosen here and there and he won’t be able to cut it in a slicing fashion, rather he will do “dirasah”. And thus one should not rest ones fingers on the knife but rather grip it by the handle so that he won’t cause “dirasah”. Even if one does not do “dirasah” with anything other than the gullet, it [the slaughter] in not acceptable. The custom is that all “dirasah” is unfit whether it be a little in the beginning [of cutting] or at the end [of cutting], whether with the windpipe or gullet.