As described in “An Oral Law at Sinai,” it seems rather clear that at least some oral laws accompanied the Written Torah text given by Moses. A minimalist approach (discussed in the article linked to above) would only argue that some oral laws were given, whereas the rest of Halacha would have been a later development in rabbinic Judaism.
These laws would have been preserved in tradition (at least by the minority who observed proper Torah-Judaism in the First Temple era – see here), and despite being so fragile, at least most of the oral laws would have likely been kept intact without error.
Yet despite this, no one can deny that mistakes are still possible—at least rarely, especially in times of struggle and national hardships. Thus Maimonides explains in his works on this topic, that if an authentic God-fearing scholar is to come and claim “thus I have heard in tradition from my teacher who received in direct tradition from Sinai”—we accept his law and must not argue. Hence, it is almost impossible to have an argument where one scholar claims the tradition is one way and another scholar claims the tradition is another.[1] Only rarely do we find an argument in this category where one sage says one way and another says another way.[i]
The Talmud typically states which laws are believed to have come from tradition to Sinai. It calls those laws halacha lemoshe misinai.[2] But even laws that the Talmud does not explicitly say that they are from Sinai, can sometimes be logically deduced to have come from Sinai.[3]
Maimonides explains that there are frequent arguments on the “hint” in the Written Torah that alludes to the tradition from Sinai. He uses the citrus fruit, the esrog, as an example. According to Maimonides, the esrog used on sukkot is a tradition from Moses at Sinai. In fact, it was such a common tradition that not a single Talmudic authority argued on the meaning of the biblical “nice fruit”; they all interpreted it to be the esrog. Yet they still argued on how this esrog interpretation is derived from the verse. They each have their own unique twist to the exegetical interpretation, but they all end up agreeing that the “nice fruit” is referring to the esrog. The meaning behind such arguments and exegetical interpretations will be discussed in “What’s Up with the Far-Fetched Interpretations.”
[1] Perhaps only in very rare specific cases is it possible. Such would be in a case where one scholar claims that he is uncertain and vaguely remembers from his teacher that such a law was from Sinai. In such a case, it would seem that it is permitted to argue on this scholar. This would explain how at times we do find an argument on traditions of Sinai).
[2] Conversely, not every time the Talmud refers to something as coming from Sinai, does it mean it literally from Moses at Sinai. Sometimes it just means that it is a tradition going back many generations, and halacha lemoshe misinai was just a term for the concept of tradition. A proof for this is the letter Shin on the Tefillin box that is said to be there because of a law from Sinai. The problem however is that the letter Shin the way we have it today was not the same as the way the letter was at Sinai. As discussed in the footnotes in chapter “Is the Torah’s Text Accurate?” the Hebrew alphabet that the we use today is sources from the Aramaic/Assyrian alphabet. But the original Hebrew language was the Phoenician alphabet (or proto-Canaanite alphabet). So if it were actually a law from Moses at Sinai to have the Shin on the Tefillin box, then we would be transgressing that by having the modern Shin instead of the original one.
Yet another great example is from Nedarim 37b. There the Talmud states that the keri and ketiv are from Moses at Sinai. The concept of keri and ketiv is pronouncing certain words different than how they are written in the text. There are different reasons for this, a broader topic we will not address here. But in any event, the Talmud is saying that it’s a tradition from Sinai which words to pronounce differently than their written format. Now, if we are to understand this literally, that Moses at Sinai told us which words to pronounce differently, we run into a huge problem. The Talmud proceeds to go through the list of words that are pronounced differently−but they are all from the Prophets and Writings, not the Torah. So how could Moses have given us the list of words in the Prophets and Writings before these books were even written. So obviously the term isn’t to always be taken literally but as an expression for “tradition going way back.”
This concept isn’t my own idea but the understanding of early rabbinic sources. See Rash on Mikvaos ch.1 and Tosfos Rash of Sens on Mishnayos Yadayim 4:3.
[3] Rambam in his introduction to the Mishnayos chapter 4 explains that in a case where it cannot be connected to the verse in any way, including with a “hint” (asmachta), the Talmud would label it under “a tradition from Sinai” even though essentially more are included in that category.
[i] Rambam in his introduction to the Mishnayos chapter 4. See also Rambam Hilchos Mamrim 1:3 the way it is explained by Chavos Yair ch. 192 and Maharatz Chayos on Bava Kamma 17b (also see Maharatz Chayos in his work titled Toras Neviim Maamar Torah SheBeal Peh chapter 1). There are many proofs for their explanation of the Rambam (the way we explained it in the body text) including dozens of disputes on matters of tradition from Sinai. Also see how the Ramabm proceeds to explain himself in his introduction by citing a Mishnah in Yevamot 8:3 “if it is a tradition from Sinai, we will accept it from you; but if it is merely a derivation of yours, we will argue.”
Mavo Letalmud (on Machalokes BeHalacha chapter 1, or page 36) brings an additional proof that disputes are possible on Sinaic laws from the argument on how to interpret the forty lashes of Deuteronomy 25:3 (see Makos 22a).
