Siman 6

Regarding the slaughter of kodashim, we hold that a vessel is required for their slaughter [Zevachim 97b], such as a knife or the like, and we derive this from the binding of Yitzchak, who was an olah, and it is written regarding him, "And he took the ma'akhelet to slaughter his son." We learn from this that an olah requires a vessel, for if not so, let it be written, "And he took the cutter" [Tosafot]. And from olah we derive there for all kodashim. However, regarding the slaughter of chullin, we do not require a vessel, and we do not derive it from kodashim, for regarding kodashim, for all their services we require a vessel of service, which is not the case regarding chullin. It is only regarding the matter of being detached, that one must slaughter with an object detached from the ground, and if he slaughtered with an object attached to the ground, his slaughter is invalid. And this we derive from the binding of Yitzchak, and so the sages, of blessed memory, said [Chullin 16a]: From where do we know that slaughter must be with a detached object? As it is said, "And he took the ma'akhelet to slaughter," for since it is not written "to slaughter the olah," we derive from this regarding every type of slaughter that it is only with an object detached from the ground [Tosafot].

And thus the sages taught [15b]: One may slaughter with anything, whether with a flint, or with glass, or with the stalk of a reed, provided only that they are sharp and checked for a notch, and also that they are hard such that fragments do not fly off from them. Therefore, the Tanna said "flint" and not merely "stone," for flint is the hardest of stones, as it is written in Ezekiel [3]: "As an adamant harder than flint," see there. Therefore, even with glass, specifically with hard ones and not with soft ones. This is what our teacher, the Rema, wrote: And it is forbidden to slaughter etc. or glass from which splinters separate, see there [and it is unnecessary to say that there is a scribal error in his words, see Shach and Taz and Kereti U-Peleti].

And also regarding the reed-crust, the sages, of blessed memory, distinguished [ibid.] that only with the crust of a water-marsh reed may one slaughter ab initio, for they are hard and splinters do not separate from them; but with other reed-crusts one may not slaughter ab initio, and there are those who forbid even ex post facto [Beit Yosef in the name of the Ittur] for the reason that even after inspection it is difficult to reach a clear determination, and it is proper to be concerned for their words, and some of the great later authorities forbade this by the letter of the law [Taz and Pri Chadash]. And even though according to the essential law it is so, nevertheless, in our days we have not heard of slaughtering with any of these things, and the simple custom in all the dispersions of Israel is not to slaughter except with an iron knife. And in these days of ours, we do not slaughter except with forged iron called steel, and in the large cities there are workshops that make them very polished, and they are choice for slaughtering as is known, and they are sharp and smooth. And every shochet must have a knife designated for slaughtering [Tur], and so it is explained in the Shas [8b], and he should not use it for anything else so that it will be clean and not become damaged [see Beit Yosef and Bach], and this is also for the honor of the mitzvah. And on Shabbat, regarding the matter of muktzeh, we say that a slaughtering knife is muktzeh according to all opinions [Shabbat 123b, Tosafot s.v. "ve-sakkina"] because it is used for nothing other than slaughtering. And now the simple custom is that every shochet u-bodek has three knives: for large livestock, for small livestock, and for poultry, for it is known that for poultry it is good to slaughter with a small knife, for small livestock with one slightly larger, and for large livestock with a very large one.

We have already written that with something attached to the ground, it is disqualified by the Torah to slaughter with it. Regarding something detached that was subsequently attached, it is the opinion of the Rif and the Rambam to validate it post facto even when he nullified it to the ground, for so it implies from the discussion of the Shas there. It is the opinion of the Rosh and the Tur to disqualify it even post facto when he nullified it to the ground, and one should be concerned for their words [Rashal and Bach]. And even according to the opinion of those who validate it, this is specifically when it has not taken root in the earth; but if it has taken root, it is like something attached from its inception [Tur].

Therefore, a reed that grows from the ground and a flint protruding from a wall, if one slaughtered with them, the shechitah is invalid according to the opinion of the Rosh and the Tur in all cases; and according to the Rif and the Rambam, specifically with a reed that grew on its own or that a person planted and it took root in the ground, and a flint protruding from the wall of a cave and not from the wall of a building.

And detached and subsequently attached, where he did not nullify it to the ground, is kosher according to all opinions; for example, if one fixed a knife into a wall and slaughtered with it, his slaughtering is kosher. This is specifically when the neck of the animal is below and the knife is above, for if the neck were above and the knife below, it is disqualified even ex post facto due to the reason of derasa, as the neck weighs down upon the knife and presses. And even if he says, "It is clear to me that I did not press," it is disqualified [Tur]. And this is specifically regarding an animal, but a bird is kosher ex post facto in any manner because a bird is light by its nature and does not weigh down upon the knife [ibid. Gemara]. And there are those who distinguish between a light bird and a heavy bird, and their reasoning is that they hold that the distinction the Gemara makes between an animal and a bird is because an animal's weight is great, and therefore they hold that with a heavy bird it is also disqualified. The Tur rejected this, as the reason is because every bird is light by its nature. And since the prohibition regarding an animal when it is above is due to the reason of derasa, there is no difference between whether he fixed the knife in a wall or whether he fixed it in a beam resting on the ground [Beit Yosef]. But when holding the knife in his hand, we have no concern with it, for behold, he does not pass the neck of the animal over the knife, but rather moves the knife under the neck, and there is no concern of derasa here. However, ab initio one should not do so, and so it is implied in the Gemara [see Shach subsection 8].

A thing attached to the body of a living creature has the status of that which is attached to the ground. Therefore, if one slaughtered with a tooth attached to any living creature, or if one slaughtered with a claw attached to any living creature, his shehitah is invalid according to the Torah. For we find regarding a person that his status is as one who is attached, as he is compared to the ground [Rashi, Kiddushin 7a]. And regarding other living creatures, even though for the matter of acquisition their status is as movable property, nevertheless they are not similar to a knife, from which we derive the invalidation of that which is attached, as I have written; and just as we exclude that which is attached, so too we shall exclude living creatures [and the difficulty of the Gara"a cited by the Pitchei Teshuvah is settled]. However, if he cut a jaw from an animal that has sharp teeth and slaughtered with one tooth, his shehitah is kosher. And similarly, if he cut a hand or a leg from an animal and it has a sharp claw and he slaughtered, his shehitah is kosher, for the fact that they are attached to the jaw or the hand or the leg is not considered as being attached. And this is specifically when he slaughtered with one tooth or one claw, but with two, the gap between one and the other constitutes a notch and makes it treif, for this is not shehitah but rather strangulation, as this is like a sickle.

A knife where one side is a knife and its second side is a sickle or a saw full of notches, one may not slaughter even with the side that is a knife, and even in a case of pressing need [Tevu'ot Shor], lest he err and slaughter with the second side. And even if he made some sort of sign for this, it is not effective unless he smoothed the second side entirely. And it is not similar to what will be explained regarding a knife that has a notch in it, where in a case of pressing need one may slaughter in a place where there is no notch and by wrapping a cloth, for there the notch is not permanent; but with a vessel where the notches are for work and they are permanent, it is forbidden forever, lest he come to err and slaughter with the side of the notches. And ex post facto, when he slaughtered with the good side, his slaughtering is kosher, for ex post facto one should not forbid because of a decree. And this is what the sages taught in the Mishnah [15b]: One who slaughters with a harvesting sickle, etc., his slaughtering is kosher—ex post facto yes, initially no [Gemara], lest he come to do it with the other side [ibid.].

A knife that has a notch in it is forbidden for slaughtering even if he intends to slaughter not with the side of the notch, and even if the knife is still large until the notch, and even if he wraps a cloth over the notch, it is forbidden ab initio. And ex post facto, if he slaughtered and said, "It is clear to me that I did not touch the notch," if he knew about it, his slaughtering is valid. And if he did not know about it at all, even ex post facto it is forbidden, for since he did not know, he passed it over it and did not notice [Taz], for any matter that is not cast upon a person, he does it without realizing. And when he knew, it is valid ex post facto even without wrapping a cloth.

Nevertheless, on Yom Tov when it is necessary to slaughter and it is forbidden to sharpen it, or even on a weekday in a pressing situation where the time is urgent to slaughter, such as for a sick person or the like, it is permitted to slaughter ab initio if he wraps a cloth over the notch. This is specifically when there remains from the location of the notch a length of two necks, for even though when one slaughters with a forward and backward motion we do not require this measure, as will be explained, here we fear lest through the forward and backward motion the cloth will be detached from its place and he will slaughter with the notch [Shach, subsection 5]. The correct approach is that on a weekday one should avoid this entirely, but rather should sharpen it; and so is the simple custom and it is not to be changed [and only for a sick person should he act according to the law].

Also, when there is a notch between the knife and the handle, one should not slaughter with it ab initio. Similarly, a knife that has a sharp point at its tip, one should not slaughter with it ab initio, lest he pierce with the point and perform haladah; and on Yom Tov, he should stick the point into a piece of wood. And a knife that has two edges, he must be careful that both edges are completely kosher.