Halakhah sobre Deuteronómio 13:1

However, Hokhmat Adam 36:1,¹³Cf., however, R. Pinchas Eliyahu Eisenthal, Ha-Maḥaneh ha-Ḥaredi, 25 Adar 5764, p. 38, who interprets Ḥokhmat Adam’s comment as referring only to the question of ḥelev of a ḥayyah in conformity with Pri Megadim’s understanding of Shakh, i.e., as ruling that a mesorah is required only to establish that the animal is a ḥayyah rather than a behemah for purposes of permitting consumption of its ḥelev. Arukh ha-Shulḥan, Yoreh De'ah 80:10, and Hazon Ish, as well as Erekh ha-Shulḥan, Yoreh De'ah 80:10 and 82:29, understand Shakh as declaring that all animals are similar to birds in that no species may be accepted as kosher in the absence of a tradition confirming its status.¹⁴Rabbi Ari Z. Zivotofsky, “Kashrut of Exotic Animals: The Buffalo,” Journal of Halacha and Contemporary Society, no. 38 (Fall, 1999), cogently draws attention to the fact that the status of the buffalo is also problematic. This may appear odd to students of Yoreh De‘ah since, basing himself on much earlier authority, Shulḥan Arukh, Yoreh De‘ah 28:4, identifies the buffalo as a kosher species. Rema agrees but, unlike Shulḥan Arukh who classifies the animal as a behemah, Rema declares that it is doubtful whether its status is that of a behemah or of a ḥayyah. That reference, however, is not to the American buffalo but to a different animal, probably the Asian water buffalo which was introduced to Europe at an early date, but possibly the European bison or, less likely, the African buffalo. The animal referred to in this country as a “buffalo” is not really a buffalo but a unique species of bison. The American bison is indigenous to North America and hence was unknown to the author of Shulḥan Arukh and certainly could not have been known to the much earlier authors upon whom Shulḥan Arukh relies. Since the animal is indigenous to the New World it is obvious that there exists no tradition with regard to its status as a kosher animal. The fact that sale of the meat of the American bison was sanctioned some years ago by a number of kashrut supervising agencies does not necessarily indicate reliance upon the position of Pri Megadim. It may signify nothing more than the understandable, albeit erroneous, assumption that the animal is identical to the “buffalo” expressly sanctioned by Shulḥan Arukh. Moreover, even Ḥazon Ish did not unequivocally brand the “Indian ox” or zebu as unacceptable but indicated that the ultimate determination must rest upon the extent of its similarity to more common cattle. Although halakhic categories and scientific classifications are by no means coextensive or even overlapping, the American buffalo is scientifically classified either as a member of the same genus as true cattle or together with the European bison. The matter can be resolved only by a comparison of the physical characteristics of the American bison with those of the cow or, assuming there is a tradition with regard to its status as a kosher animal, the European bison.
Cf., R. Israel Belsky, Mesorah, no. 20 (Adar 5764), who writes that Ḥazon Ish would have permitted the American bison because it should be considered to be an “ox.” That allegation is entirely unfounded. Zebu, forbidden by Ḥazon Ish are far more similar to cattle, both zoologically and in terms of gross appearance, than are bison. Cf., Halacha Berurah, published by Zeirei Agudath Israel, vol. 7, no. 3, p. 3 and p. 4, note 24, in which R. Belsky himself acknowledges that the American bison is not permissible according to Ḥazon Ish.
Parenthetically, the Gemara, Bekhorot 7a, states that a ḥayyah and a behemah cannot mate and produce progeny. Accordingly, the phenomenon of the “beefalo,” a cross between a buffalo and a cow whose meat is commercially available, should demonstrate that the American buffalo is a behemah rather than a ḥayyah. There appears to be no available information with regard to whether any of the other species of buffalo to which Rema may have referred can be crossbred with cattle. Hazon Ish professes that "it is not incumbent upon us to seek reasons" for this stringency¹⁵R. Joseph Ber Soloveitchik, author of Bet ha-Levi, is quoted in Netivot Rabboteinu le-Bet ha-Levi Brisk, II (Jerusalem, 5763), 102, as stating, “for without a ‘masoret’ it is impossible to permit an ox, even if all the known characteristics are present, with the argument that it is the ox of which the Torah speaks.” The statement was made in the context of identification of the ḥilazon. Bet ha-Levi cites the verse, “Ask your father and he will tell you, your elders (zekenekha) and they will say to you” (Deuteronomy 32:7) and explains the apparent redundancy in the two clauses as follows: The term “zekenekha,” generally rendered as “elders,” also means “wise men.” In this instance it clearly has the latter meaning, i.e., the “wise men” are charged with responding to questions of Halakhah. The first clause, however, speaks of questions addressed to a father who must transmit the answer. The subject of that question addressed to fathers rather than Torah scholars, declares Bet ha-Levi, is empirical in nature, i.e., a matter of fact (meẓi’ut) upon which Halakhah is predicated that must be transmitted by means of a tradition passed down from generation to generation. but that it probably arose in order to prevent error with regard to identification of an unfamiliar species as a ḥayyah or as a behemah and consequent inadvertent transgression with regard to ḥelev or covering the blood. Hazon Ish also asserts that it serves to prevent transgression with regard to the prohibition of treifot that is attendant upon certain anatomical anomalies.¹⁶Thus, on the basis of the reasons for the prohibition spelled out by Ḥazon Ish, the fact that the zebu can hybridize with cattle is entirely irrelevant. Rabbi Zivotofsky, “Kashrut of Exotic Animals,” pp. 126–127, seems to have missed this point. Cf., Halacha Berurah, vol. 7, no. 3, p. 3 and p. 4, note 27. Moreover, whether the basis of this halakhic position is fear of genetic mutation, possible treifut or some other consideration, it is clear that Shakh and those who follow his ruling declare that, in the absence of a mesorah, the biblical criteria of a kosher species, i.e., a split hoof and chewing of the cud, cannot be relied upon in establishing the kashrut of a species. If biblically prescribed criteria that tautologically define kosher species are for some reason unacceptable, a fortiori, a rabbinically recognized criterion that is merely emblematic of the presence of defining criteria cannot be acceptable. Thus it is not surprising that neither Shakh nor any authority following in his footsteps indicates that the hybridization phenomenon serves as a substitute for a mesorah. Nor, to my knowledge, is there any authority who accepts the hybridization phenomenon as a substitute for a mesorah with regard to birds.
In a letter to the editor published in Tradition, vol. 36, no. 2 (Summer, 2002), p. 108, Rabbi Zivitovsky claims that “… many authorities have been willing to rely on the hybridization principle to rule that a bird species is kosher even in the absence of a tradition (see the discussions in, e.g., Ḥatam Sofer, Yoreh De’a 74; Netsiv, Meshiv Davar, Yoreh De’a 22; Avnei Nezer, Yoreh De’a 1:75; Maharsham, Da’at Torah, Yoreh De’a 82:3). That being the case, it would seem that, kal va-ḥomer, the hybridization principle should govern in the case of animals, for whom the tradition requirement is less certain and generally considered a stringency of recent vintage.” Rabbi Zivitovsky reads into the first three sources that he cites much more than they contain. The fourth source, Da‘at Torah of the Maharsham, contains nothing of relevance to this discussion.
Each of the sources deals with problems associated with one or more species of wild duck or wild goose. Although accepted by Ẓemaḥ Ẓedek, Yoreh De‘ah, no. 60, as a member of the same species as the domestic duck or goose, the majority of rabbinic authorities of the day regarded the fowl under discussion as significantly different in its physical characteristics from the species recognized as kosher and, in the absence of a mesorah, refused to recognize the wild duck as kosher. [See, however, R. Yonatan Eybeschutz, Peleti 82:2 and Kereti 82:9, who refers to the bird as a “wild goose” and rules that it is a kosher species.]
Some ducklings of that species were permitted to mingle freely with domestic ducks. The question posed to Ḥatam Sofer was whether future born ducklings born to female domestic ducks were to be regarded as kosher since the fathers may well have been members of unacceptable species of wild duck, Ḥatam Sofer permitted those offspring on the basis of a combination of a number of considerations: 1) Ẓemah Ẓedek ruled that the wild duck was a permitted bird; 2) the ducklings had the physical characteristics of the mother duck, indicating that the father was probably of the same species; 3) the majority of male ducks having access to the females were of the kosher species; and 4) whether or not paternal status could render the offspring non-kosher (ḥosheshin le-zera ha-av) is itself a matter of halakhic doubt. For purposes of the present discussion, the crucial point is that Ẓatam Sofer did not rule that successful hybridization served to confirm Ẓemah Ẓedek’s ruling beyond cavil. Ḥatam Sofer regards the wild duck as a non-kosher bird despite the fact that it was capable of breeding with a kosher species. Indeed, Ḥatam Sofer explicitly affirms that hybridized progeny of that bird are also non-kosher; his lenient ruling is based in part upon the probability that the ducklings in question were not hybridized but sired by a kosher duck. Thus, Ḥatam Sofer clearly refuses to accept the hybridization principle as a substitute for the requisite mesorah.
Meshiv Davar addresses the status of an apparently different species of duck that had been accepted as kosher in some locales. His interlocutor points out that those ducks mate freely with species of duck accepted as kosher. Although Meshiv Davar accepts the species as kosher for a number of reasons, including the fact that it shows no preference whatsoever for its own species over partners from the domestic species, he explicitly rejects the hybridization principle as dispositive with the comment “… for we accept the wild duck as unclean [despite the fact that] it procreates from our duck.”
Rabbi Zivitovsky fails to cite Avnei Nezer, Yoreh De‘ah, no. 76, dealing with a particular species of duck or goose in which he notes that they breed with kosher species but nevertheless, without citing Bekhorot 7a, comments that, since the two species are housed together for breeding purposes, the fact that they mate does not establish the kashrut of the species. In the very next paragraph he then queries how any bird can be regarded as kosher since it may have a non-kosher progenitor and offers several resolutions to that problem. Quite obviously, Avnei Nezer does not accept the hybridization phenomenon as a substitute for a mesorah.
Avnei Nezer, Yoreh De‘ah, no. 75, discusses an apparently different species of duck. It seems that the only physical characteristic of the species in question that gave Avnei Nezer pause in issuing a permissive ruling was that, unlike other ducks, its quack was “hoarse.” Avnei Nezer points to the fact that the duck in question breeds with accepted duck species as indicating that they are truly the same species. In that responsum there is no evidence that he would have accepted the hybridization principle as independent validation of the kashrut of the bird in situations in which its physical characteristics were markedly different from an accepted species. Read together with the immediately following responsum, that conclusion is inescapable.
Parenthetically, Ḥatam Sofer and others express some reservation with regard to the applicability of the hybridization principle of Bekhorot 7a to birds. In context, the principle is formulated with regard to animals and hence its extension to birds is a matter of at least some doubt. Thus, logically, grounds for application of the principle to animals are stronger than for birds. However, methodologically, Rabbi Zivitovsky is quite correct. Since Shakh’s requirement of a mesorah to animals is simply an extension of the rule accepted with regard to birds, any alternative mode acceptable with regard to birds should therefore be acceptable with regard to animals as well.
However, since no authority accepts the hybridization phenomenon as an alternative to a mesorah with regard to birds, there is no evidence supporting its acceptability with regard to animals. In light of both Shakh’s failure to regard the hybridization phenomenon as an alternative to a mesorah and Ḥazon Ish’s formulation of the reasons underlying Shakh’s stringency which, as Rabbi Zivitovsky himself candidly concedes, apply with equal cogency in the presence of hybridization, there is simply no basis for concluding that, according to Shakh, hybridization is other than an irrelevant phenomenon. Those anomalies, he claims, particularly with regard to certain structures of the lung, are difficult to recognize in unfamiliar species.¹⁷Refraining from an act because of fear of actual transgression, even if such fear is unwarranted, or as a seyag or “fence” designed to prevent transgression in other instances does not involve transgression of “You shall not add thereto” (Deuteronomy 13:1). The statement to the effect that Rabbi Herzog suggested that those who require a tradition confirming the kashrut of an animal species are in violation of this commandment is misleading. See Rabbi Zivotofsky, “Kashrut of Exotic Animals,” p. 126. Rabbi Herzog expresses doubt with regard to whether a “rebellious elder” (zaken mamre) who forbids the meat of such an animal, contra a formal ruling of the Great Sanhedrin, is in violation of the prohibition. Such an individual does not incur capital punishment for issuing a ruling of that nature since the matter cannot result in a transgression involving the penalty of excision (karet) on the part of any person who obeys his ruling. Rabbi Herzog expresses doubt with regard to whether, despite the absence of capital punishment, a person ruling in such a manner nevertheless violates the commandment “You shall not add thereto.” It may also be suggested that the consideration reflected in this practice is a fear that an unknown species may, in reality, be the product of genetic mutation of a progenitor that itself was a member of a non-kosher species. Progeny of non-kosher animals are non-kosher even if such progeny manifest all the indicia of kosher species.¹⁸For a fuller elucidation of this point see this writer’s “The Babirusa: A Kosher Pig?” Contemporary Halakhic Problems, III (New York: 1989), 66–67.

To not add to the commandments and their understanding: That we were prevented not to add to the written Torah, nor to the oral Torah. And about this is it stated (Deuteronomy 13:1), "do not add to it." And how is the addition? Rambam, may his memory be blessed, wrote (Mishneh Torah, Laws of Rebels 2:9), "For example, one who instructs that chicken meat with milk is forbidden by Torah writ - that is adding upon the word of the received tradition. As so did we receive about the understanding of 'you shall not boil a goat, etc.' - that the meat of a [domesticated] beast and a [wild] animal are forbidden to cook in milk, but not chicken meat. And so [too,] if he instructed that meat from a [wild] animal is permitted with milk, he has transgressed on account of 'you shall not subtract.' As this is subtracting, since so did we receive [about the verse's understanding], that the meat of a [domesticated] beast and a [wild] animal are [both] included in the prohibition." To here [are his words].

To not subtract from the commandments of the Torah: That we were prevented from subtracting a thing from that which the perfect Torah commanded us. And about this is it stated (Deuteronomy 13:1), "do not subtract from it." And how is this prohibition? For example, that which they, may their memory be blessed, said in the third chapter of Rosh Hashanah 28b that if blood that requires one sprinkling is mixed up with blood that requires four sprinklings, "Rabbi Eliezer says, 'It is to be sprinkled four times.' And Rabbi Yehoshua says, 'It is to be sprinkled once - since when you sprinkle four times, you transgress, "do not add," and you perform an act; whereas when you sprinkle once, even if you transgress "do not subtract," you do not perform an act.'" To here [is the excerpt from the Talmud]. We know from this that the negative commandment of 'do not subtract' is in this way and all that is similar to it.