As we learned on yesterday’s daf (=page), a law derived by means of a hekesh (a word analogy) – like the law that thehatat, the sin-offering, must be slaughtered in the northern part of the Temple courtyard, which is derived from the clearly stated law regarding an olah, the burnt-offering – cannot be used to teach that law by means of another hekesh – like using hatat as a source for the law for the korban asham, the guilt-offering.
The Gemara on today’s daf examines whether this rule is true in all cases where the source of the original law is not a clear biblical passage, but is learned by means of some exegetical derivation. For example, can something learned from ahekesh be used to teach based on:
- a gezeira shava?
- a kal vahomer?
- a binyan av?
All of these methods of analysis are among the midot she-haTorah nidreshet bahem – the exegetical principles established by the Sages and used to derive laws from the Torah. These specific examples are used as follows:
Hekesh – is an analogy. When two cases are mentioned together in the same passage or in adjacent passages, we can assume that since they are juxtaposed, they are analogous. For this reason, legal inferences may be drawn by comparing the two cases. On rare occasions, such as in our case, the analogy may be stated explicitly in the Torah.
Gezeira shava – is a verbal analogy. If the same word or phrase appears in two places in the Torah, we may infer on the basis of “verbal analogy” that the same law must apply in the other case, as well.
Kal vahomer – is an a fortiori inference. This is a rule of logical argumentation by means of which a comparison is drawn between two cases, one lenient and the other stringent. Kal vahomer asserts that if the law is stringent in a case where we are usually lenient, then it will certainly be stringent in a more serious case; likewise, if the law is lenient in a case where we are usually not lenient, then it will certainly be lenient in a less serious case.
Binyan av – is an interpretation based on induction. While there are different types of binyan avs, the simplest form ofbinyan av follows the logical pattern “just as we find in Case A that Law X applies, so too we may infer that in Case B, which is similar to Case A, law X should apply.”