The 13 Rules of Rabbi Ishmael

 

Some of the laws contained in the oral Torah are derived from the written Torah by means of these 13 middot (meaning “measure”). According to the rabbinic tradition, these laws were given to Moses at Mount Sinai. However, there is a disagreement as to whether parts of the oral Torah were lost and then “recreated” using these rules (the view of Ohr HaChaim), or if God simply gave these principles to Moses in order to use in the transmission of the oral Torah without anything being lost (the view of Maimonides). It seems that the view of Maimonides is more in line with the teaching of the Talmud, for it says: “It is taught in another baraita: ‘Because he has despised the word of the Lord’; this is a reference to one who says the Torah did not originate from Heaven. And even if one says the entire Torah originated from Heaven except for this verse, i.e., any one verse, claiming that the Holy One, Blessed be He, did not say it but Moses himself said it on his own, this is included in the category of: ‘Because he has despised the word of the Lord.’ And even if one says the entire Torah originated from Heaven except for this inference inferred by the Sages, or except for this a fortiori inference, or except for this verbal analogy, this is included in the category of: ‘Because he has despised the word of the Lord.’” (Sanhedrin 99a)

“When God gave Israel the Torah, He presented it only in the form of wheat and flax, leaving us to extract flour and make a garment.” (Seder Eliyahu Zutta)

The Talmud records that these principles were passed down by the rabbis and members of the Sanhedrin, each to each other. At times they were forgotten by even the most prominent sages, and had to be restored yet again: “The Gemara relates: When Rabbi Yehuda HaNasi would learn thirteen aspects of a halakha on a certain issue, he taught Rabbi Ḥiyya seven of them. Ultimately, Rabbi Yehuda HaNasi fell ill and forgot all thirteen aspects. Rabbi Ḥiyya restored those seven aspects that Rabbi Yehuda HaNasi taught him by reviewing them before Rabbi Yehuda HaNasi. However, six were gone and forgotten, as Rabbi Yehuda HaNasi had not taught them to anyone. There was a certain launderer who would hear Rabbi Yehuda HaNasi when he was studying those halakhot. Rabbi Ḥiyya went and learned those halakhot from the launderer and he came and restored them by reviewing them before Rabbi Yehuda HaNasi. When Rabbi Yehuda HaNasi saw that launderer, Rabbi Yehuda HaNasi said to him: You made me and Ḥiyya, as we were able to learn these halakhot that otherwise would have been forgotten. Some say that this is what he said to the launderer: You made Ḥiyya, and Ḥiyya made me.” (Nedarim 41a). Rashi here refers to these as the “methods of interpretation”, although the Tosafists prefer to say that it may simple be 13 diverse approaches in which one may examine a single halakhah, or how that law may be derived using the 13 rules of Ishmael (see the commentary of Rosh). 

These rules of Rabbi Ishmael are contained in a baraita found in the Sifra (the Midrash halakhah on Leviticus). They are also recited in the daily Jewish prayers. Though these are peculiar to the Jewish study of halakhah, some of them are also similar to the 32 rules of Aggadah from Rabbi Eliezer ben Rabbi Yosi the Galilean, one of the tannaim in the 2nd century. They are listed out in full by Rabbi Samson ben Isaac Chinon in his Sefer Hakeritot, and by Rabbi Nathan Cardozo in The Written and Oral Torah: A Comprehensive Introduction, pages 178-187. 

[1]. Kal Vachomer - This principle is quite similar to an argument a fortiori from the lesser to the greater. The rule teaches that any strict details found in a lenient case certainly apply to the stricter case as well. The reverse is also true (Introduction to the Talmud: Histories, Personalities, and Background [Mesorah Publications, 2019], pg. 12). Scriptural examples are found in Genesis 44:8; Exodus 6:12, Deuteronomy 31:27.

Example: The Torah commands a person to pay damages done by his animal. According to the rule of kal vachomer, if the Torah obligates a person to pay for damages committed unintentionally by his livestock, then surely also he is obligated to pay for damages done intentionally by his livestock (Bava Kamma, 4a). 

It can be hard to determine between two cases which is more strict and which is more lenient. A concrete example can be seen in part of the Talmud, which compares the first-fruits offering (bikkurim) with the maaser sheni tithe. The former can only be eaten by the priest, while the latter can be done by the people. Therefore, the first-fruits offering is handled more strictly than the maaser sheni tithe. In one sense, the maaser sheni is dealt with strictly, since it can only be eaten inside Jerusalem. Therefore, the Talmud uses the rule of kal vachomer to conclude from this that the bikkurim can only be eaten in Jerusalem too (Makkos 17a). Later on, the Gemera rejects this rule by pointing out that the maaser sheni has certain strict rules which the first-fruits offering does not have (Makkos 17b). 

This rule is limited by the principle of dayyo—which means that the law being applied in the strict case cannot be more strict there than it is in the lenient case. Ex: Numbers 12:14 - “And the Lord said unto Moses, If her father had but spit in her face, should she not be ashamed seven days? let her be shut out from the camp for seven days, and after that let her be received in again.”

[2] Gezeirah Shavah - When there are two passages in the written Torah which use the same Hebrew word or form of the word, then the law of the one passage may be used in interpreting and applying the law of the other passage. This is true even when the laws do not appear to be topically related to one another.

Example: Numbers 28:2 states that the tamid offering must be offered in its “appointed time.” (בְּמוֹעֲדֽוֹ). This same word בְּמוֹעֲדֽוֹ is also used in Numbers 9:2 when referring to the Passover offering. However, the Torah does not say whether the Passover offering cannot be offered on the Sabbath (if it falls on the Passover that given year). However, the rule of gezeirah shavah states that since the same word is used in these two sects, we can apply the principles of the tamid offering to the Passover offering, concluding that it is permissible to offer the Passover sacrifice on the Sabbath, despite the general prohibitions on animal slaughter on that day. 

The rule of gezeirah shavah is also applied when two texts have the same/similar concept, even if the same word is not used. 

Two identical words being used per se does not form a gezeirah shavah. A tradition going back to Moses is required: “The Gemara explains that this is what happened: Hillel first told them the a fortiori inference, but they refuted it and proved that it was not reliable, as explained above; and then he told them the verbal analogy, and a verbal analogy is based on an oral tradition originating from Moses at Sinai and must be accepted.” (Pesachim 66a)

[3]. Binyan Av – When the Torah commands a certain law on a specific case, the law is applicable to other cases of a similar nature by a reasonable comparison. For example: If a vessel becomes ritually impure through contact with a dead animal (Lev. 11:29-30), then it is made pure again by immersion in a mikveh. However, we do not read how to purify things made impure by other sources. The principle of binyan av tells us that the similarity of the two topics means that other things are made pure by immersion into a mikveh (Maimonides, Mishneh Torah: Mikvaot, 1:2).

[4]. Klal Uprat - If the Torah is discussing a law and begins with a general broad term, and then uses a specific term(s), the specific term should be read literally, and the law is limited to whatever is included in that term. The broad term includes only that which is mentioned in the specific term.

[5]. Perat U’klal - This pertains to when a specific term is followed by a broad term. In this case, the broad term “adds on” to the specific term. By writing the specific term first, the Torah is teaching that everything implied in the broad term is included in the law (Maimonides, Mishneh Torah: Halichos Olam, 4:26). 

The rest of the rules will be listed by their English names, since the original Hebrew is too long.

[6]. A Broad Term followed by a Specific Term, then Followed by a Broad Term - The rule is that the law or case can be applied only to things which are included in the specific term (Halichos Olam, 4:27). For example, Deuteronomy 14:26 says that “And thou shalt bestow that money for whatsoever thy soul lusteth after, for oxen, or for sheep, or for wine, or for strong drink, or for whatsoever thy soul desireth.” Based on this rabbinical rule, the verse means that the money from the maaser sheni tithe can be used by anything denoted by the specific term of this text (“oxen, sheep, wine, strong drink…”), i.e. anything which reproduces and is nourished by the earth (Eruvin 27b). This rule also applied to when the Torah writes a specific term after two broad terms (Bava Kamma 64b).

[7]. A Broad Term that requires a Specific Term, and a Specific Term that Requires a Broad Term - This rule is when a broad term is used which needs clarification, and the specific term following it is merely providing that needed explanation (and vice versa!). For example, when talking about the command to cover up the blood of slaughtered animals, Leviticus 17:13 states “He shall even pour out the blood thereof, and cover it with dust.” The Gemara uses this rule to show that this verse is not limiting to earth only, but the term “he shall cover it” is a broad term needing clarification, since “cover” can mean different things in this context (Chullin 88b). 

With regard to all of the rules involving “broad terms” and “specific terms”, there are some Rabbis who maintain that we should rather interpret the Torah as speaking of “inclusive” and “exclusive” terms (Shevouth 26a). 

[8]. Something that was included in the Broad Term was also singled out for the purpose of teaching a law - There are parts in the Torah when it uses a broad term discussing a law, and then singles out a specific thing already included in the broad term. This rule maintains that this is not redundant, but has a purpose for Jewish law.

This rule teaches that the things which apply to the specific thing singled out after the broad term also apply to everything included in the broad term. Example. Exodus 22:17 commands the execution of witches engaging in black magic. However, this verse does not tell us which method of execution should be used. In Leviticus 20:27, it states that practitioners of black magic (ov and yoni) should be killed with stoning. This teaches us that witches in general are to be killed with stoning specifically (Sanhedrin 67b). 

[9]. Something that was included in a Broad Term and was singled out for the purpose of discussing a law that was previously applied to the Broad Term - This principle deals with instances in which the Torah uses a broad term when discussing a set of laws, and then singles out a specific term (included in the broad term) and only repeats some of those laws. The repetition of those laws seems redundant, since the entire set of laws was previously applied to the specific term and everything else which is included in the broad term. This rule maintains that only the repeated laws apply to the singled out term; the rest of the laws for the broad term do not apply to it. Example: Leviticus 13:2 says that the laws of leprosy apply to any form of impurity (tzaraas) – a broad term. Later on, verses 18-28 discuss particular types of tzaraas appearing on burnt flesh and a part of the body which had a boil on it. Since these types of impurity fall under the broad term, only the repeated laws apply to them individually. 

[10]. This rule deals with something that was included in a broad term, but singled out in order to discuss a completely new law. In this situation, this rule teaches that “the specific item was singled out in order to exclude it from the previously written laws, and to apply to it the laws that were specifically written regarding it.” (Halichos Olam, 4:35). 

[11]. Something included in a Broad Term is singled out in order to discuss a New Case - In this situation, the broad term is discussing a set of laws, but then a specific term is singled out and a law is given which contradicts the previous laws. The rule teaches that this specific term is an entirely independent case, and none of the laws pertaining to the broad term apply to it. The specific item cannot be reincluded into the broad term unless Scripture explicitly does so.

[12]. Using Context to Explain Unclear Verses - In Sanhedrin 86, the commandment “Thou shalt not steal” (Ex. 20:13) is discussed. It is not immediately clear if this is referring to theft or to kidnapping. However, the Gemara argues that since this commandment occurs alongside the laws against murder and adultery (capital crimes), then this commandment is speaking of a capital crime. Therefore, kidnapping is what is prohibited by the 8th commandment. The Church, of course, would rightly reject this interpretation. 

[13]. Reconciling Contradictory Passages - If two verses appear to contradict each other, they can only be reconciled by appealing to a third verse (Middot Aharon, 16). For example, Numbers 7:89 says Moses entered the tent of meeting, while Ex. 40:35 says he was not allowed to do so. This is reconciled by quoting the rest of Ex. 40:35, which specifies that it was only when the Shekhinah was present that Moses was not allowed to enter.

These 13 rules of Rabbi Ishmael constitute the standardized Talmudic approach to biblical exegesis. However, there is a disagreement amongst the Jews as to whether those laws derived by means of these rules are to be considered as properly biblical or not. In his Sefer Ha-Mitzvot, Maimonides denies this, but Nachmanides affirms that “it is proper to say that just the opposite is true, i.e. that every matter deduced in the Talmud by means of one of the thirteen canons is Biblical unless the Talmudic sages have specifically stated that the textual connection is asmakhta.” (Nachmanides, Hassagot ha-Ramban al Sefer ha-Mitzovt, ed. Pardes, pg. 40). It appears that most authorities in Jewish tradition lean towards the view of Nachmanides (Menachem Elon, Jewish Law: History, Sources, Principles, 1:210)