The Talmud is full of the standard procedure of the Sages interpreting Tanakh verses to learn various laws and behaviors.

Is there a way to tell when a Rabbi cites a Pasuk as a traditionally known מקור for a law (Torah law from Moses, like "כבד את אביך ואת אמך" as the source for honoring parents Mitzvah) or as a mere אסמכתא (rabbinic law using verse as a bassis) for his own opinion?

  • 6
    This is an excellent question! Usually we consult Rishonim, and there are often disagreements, so I would guess not. However, IIRC, there are sometimes indications in the language... Aug 7, 2018 at 21:47
  • While I don’t have a clear source for this, it seems clear to me from various sugyos that if two or more (usually eleven or twelve in these types of cases) Amoraim bring differing sources to a principle, the Gemara will always ask “what’s the difference?” If the Gemara fails to ask that question, it’s usually a good indicator that it’s an Asmachta. I’m not posting this as an answer because it doesn’t help in cases where the Gemara only brings one passuk.
    – DonielF
    Aug 8, 2018 at 2:46
  • @DonielF In case of a מחלוקת it is obvious, but with single sayings it is very hard to tell
    – Al Berko
    Aug 8, 2018 at 10:59

2 Answers 2


HaRav Moshe Ben Yosef Trani (16th century contempory of Rav Yosef Cairo) wrote Kiriat Sefer on the Rambam which is dedicated to ascribing which laws are Derabbanan and which are Min haTorah. When studying Gemora look at the small Hebrew letter adjacent to the saying e.g. א. Then look at the margin in the Ein Mishpat for א which will say for example: מיי׳ פ׳ח שבת ה׳א a reference to the relevant chapter and Halacha in Maimonides (Rambam) which you can look up in Mishne Torah. Then look up the corresponding Kiriat Sefer on the very same Halacha which will indicate if it is an Asmachta derabanan or Mideoraisa.

  • Does this address machlokos between the Rishonim when some hold a Halacha is d’Oraisa and some hold it’s d’Rabbanan, or does it just follow one Rishon’s opinion?
    – DonielF
    Sep 18, 2018 at 17:00
  • @DonielF if you would like to add another queston "when do the Rishonim argue that some hold a Halacha is d’Oraisa and some hold it’s d’Rabbanan" and then i could try and give you a few examples i know where the Rambam differs from other rishonim. But if you look up the vast majority of times you will find that they all agree about what is deoraita and derabanan. So yes Kiriat Sefer addresses the Rambam but its an incredible guide for the perplexed about what is an asmachta and what is deoraita.
    – user15464
    Sep 20, 2018 at 0:31
  • I wasn’t intending to ask a different question; I was just curious about this Sefer I’d never heard of before.
    – DonielF
    Sep 20, 2018 at 1:55
  • 2
    @donielf in a lot of older editons of Mishne Torah it kiriat sefer appears at the back of each volume, unfortunately the modern editions including frankel edition which people use today, they cut the peirush out. Chaval al deovdin...you can use the link to access the sefer, i hope you gain much knowledge from it!
    – user15464
    Sep 20, 2018 at 2:05

Shalom u'vracha! There are a few ways to tell. Generally, Torah law is explicit and limited to it's simple explanation. Drashot, asmachtot, and the like are more inclusive in their extrapolation to include what's not explicit. Halachot l'Moshe m'Sinai are Torah laws that have no explicit source but are recognized as fact due to their historical presence since the giving of the Tradition.

"En hamikra yotze midei pshuto" means that you must take the meaning of the pasuk for it's face value unless we have a tradition from Chazal that the true intention or tradition of understanding it is different than it's pshat/simple explanation. Drashot that expound a pasuk that don't fit with it's simple explanation in the name of one Rav/Tana/Amora, is likely an asmachta.

The practice of using the mikra to derive new or old teachings developed when the tradition of Torah began to weaken over the years from the time of matan Torah. The Chachamim of each generation were forced to revert to expounding the Written Torah in order to learn or revive the original Tradition that wasn't widely practiced. What was practiced, was generally law. New questions that weren't generally practiced, had to be learned through the expounding of the Written Torah according to the tradition they had, or learned, to derive the din. So when Chazal wished to introduce a Rabbinic law, they used their methods of expounding(to a lesser, but still authoritative, extent) to source their institution from a pasuk; like that of the Written Torah. The Rishonim are a good source to test whether a drasha is an asmachta or not, even though there are disagreements.

But the basic test is examining how close the drash is to the simple explanation of the pasuk. If it's not, it's likely an asmachta; unless the tradition dates back to matan Torah.*This clarification is not binding on every drash! It's merely a general guideline to differentiate between a mekor and an asmachta."

  • 1
    @ShmuelBrin Hence the final sentence in the post.
    – DonielF
    Aug 22, 2018 at 2:09
  • 1
    @chacham Welcome to Mi Yodeya! Is this your own thought? I feel that the real answer is not your concluding paragraph “but the basic test...” but rather the immediately preceding sentence “the Rishonim are a good source...” I almost might recommend trimming the entire rest of your answer off and focusing solely on that line alone.
    – DonielF
    Aug 22, 2018 at 2:11
  • @DonielF It is based on the rule discussed above("en hamikra yotze midei peshuto") in comparison to drashot by other Tanaim & Amoraim. The Rishonim also learned the Talmud and Written Torah according to this rule. However, since they were closer to the time of redaction of the Talmud, and that of the masoret from Matan Torah, their assertions have more weight and are a good place to begin. Aug 22, 2018 at 9:20
  • So in general, by "There are a few ways to tell" you mean "There are a few ways to guess"
    – Al Berko
    Aug 22, 2018 at 13:21
  • 1
    1. if you use "probably" - it IS a guessing game 2. Me and you, we don't interpret it simply the same
    – Al Berko
    Aug 22, 2018 at 13:42

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .