In exegetic and Jewish legal literature of all generations, and also in Hebrew of our times, the term qal wa-homer is a clear didactic method whose logic is clear and not subject to question. In Rabbinic literature the term represents the most serious and highest ranking of the exegetical tchniques. It is the first among the thirteen exegetical principles in the braita of Rabbi Yishmael at the beginning of the sifra. The thirteen exegetical principles are explained in various frameworks and contexts: in the midrashic explanations on the Sifra, in the explanations  in the  prayerbook where this braita appears, in the morning prayers, in the frameworks of Torah commentaries, in extensive Talmudic commentary and especially in the type of literature called “literature of rules”.

‘Dayyo’ as a part of the rules of restriction

    Tanaim and Amoraim establish rules for correct management and application of qal wa-homer. We find, for example, the following rules: 'You do not punish from a derived law', 'You do not warn from a derived law',  'You do  not reason by way of a qal wa-homer from an Oral law', 'One may not derive a gezera shava from itself but you may derive a qal wa-homer from itself '. But the general principle of dayyo ("it is sufficient" ) is a general rule governing the derivation of qal wa-homer. In the Talmudic Encyclopedia this rule is explained in the following manner “In something that is learned from something else in a qal wa-homer, one cannot have more stringencies than it has in the source”. In other words, the principle of dayyo limits the power of what is learned from a qal wa-homer in that which is learned is limited by the power of what is taught.


The qal wa-homer developed and reached its methodological peak in the generations of the first Tannaitic period

    This research strengthens the general widespread research understanding that the exegetical principles developed over the generations. They had achieved their zenith in the times of the first

Tannaic periods. The development in the methodology of the exegetical principles is                     characterized by formalization and conceptualization. The first principle: qal wa-homer, the highest ranking principle, also went through similar developmental stages. Against this background, it is possible to answer a number of questions and queries that concern this principle in Tannaitic literature.

Suggiot ‘ qal wa-homer and dayyo’ in Tannaitic sources


    As to the existence of the principle, we find many Tannaitic sources, among them applications of the principle of qal wa-homer in that what is learned is more stringent than what is taught. In an opposing manner the principle of dayyo limits the power of what is learned from a qal wa-homer. These topics or passages are called in the framework of this paper ‘Passages of qal wa-homer and dayyo’(Suggiot). These topics or suggiot which will be dealt with in depth in this paper and are divided into 2 types of sources: sources from the Mishna and Tosefta and sources from Midrashei halacha and Babylonian Braitot.  In the first group of sources we found Tannaitic arguments in the topic of the principle of qal wa-homer and dayyo. In the second group there were no arguments in the topic of qal wa-homer and dayyo. Here we find applications of the rule of dayyo. In these sources, the form of application of this rule is didactic: how and in which applicable way the rule is applied in various halachic ways. In addition to these sources, there are two further sources that have no Tannaic arguments regarding the qal wa-homer and dayyo. But the Amoraim (in one source) and the Rishonim (in the second source) establish the Tannaic disputes in these sources on the type of application of qal wa-homer and dayyo.


In all the other Tannaic passages (Mishnah, Tosefta, and Babylonian Braitot) that deal with the exegetical principle of qal wa-homer (about 250 in number) there is no reference or exact application of the rule of dayyo. It is possible that in these passages the qal wa-homer does not relate to teach a striction from what is learned. There is no necessity for the limitation that stems from the attribute of dayyo.

Restriction of ‘dayyo’  was formed as a reaction to the development of the complex qal wa-homer

    This paper will prove that the complex qal wa-homer developed from the Biblical qal wa-homer (popular and simple). This development came to be expressed in a mistaken form and in the formalization of the exegetical principles, that enabled the establishment of new forms of qal wa-homer, among them that which is learned is stricter than that which is taught  (=enhanced qal wa-homers). The rule of dayyo that resulted from this reaction, was initially a rule that refutes the qal wa-homer. In the course of time, this limited the power of the qal wa-homer and at the end it became an independent midrashic exegetical principle like the qal wa-homer itself.

There was a continuous  symbiotic relationship between qal wa-homer and dayyo


    From the particular deliberation of the passages of Tannaitic qal wa-homer-dayyo, it seems that a symbiotic relationship arises between the development of the complex qal wa-homer and the various applications of the rule of dayyo. When the general rule of dayyo was established in the beginning by R. Eliezar, it served principally as a methodological rule in the hands of R. Eliezar to prevail in  his argument between him and the rabbis in the passage of Niddah (this equals dayyo that refutes the qal wa-homer).  But in the continuum the rule of dayyo served as the principal methodological


tool to prevent an exaggerated development in the complex qal wa-homer. The story of dayyo is essentially the story of the complex qal wa-homer.

     In the continuum of Tannaitic experiments that continued until the generation of R. Meir there were experiments to make an enhanced qal wa-homer, that could not be influenced by dayyo. In these experiments, that came to expression in the following manner: on one hand-development with complex qal wa-homer and on the other hand, forms of various applications of the rule of dayyo that restrained this development.

Various forms of application to the rule of dayyo, as a reaction and as harmonization of the developing elements of the complex qal wa-homer

        This paper presents in a detailed way the midrashic technicalities that Tannaim created to achieve a complex and enhanced qal wa-homer on the one hand and on the other hand, applicable and methodological ways for the principle of dayyo to restrain this. It turns out, that the designation of the principle and its application changed. The rule changed from an 'eternal tool' to a midrashic principle that can be considered almost 'independent', that helps determine the boundaries of the complex qal wa-homer. There were Tannaim who introduced into the formal pattern of the qal wa-homer and dayyo non-biblical laws. Also laws were formed before the formulation of the principle. Under 'the legal umbrella' of containment of the the enhancement  of the qal wa-homer, it is found that Tannaim used the qal wa-homer to achieve various goals. For example: a requirement of consistency in the process of interpretation of the qal wa-homer, simplification of the logical mechanism in the interpretation of the complex  qal wa-homer, and completion of halachic missing  details that are not possible to learn within  the qal wa-homer itself. The exegetical principle became fixated and amassed midrashic strength so strong that there were Tannaim who maintained that the Torah itself recognized the great capabilities of the exegetical principle and accordingly it determined its wording.