Traditional rules of interpretation.
A Midrashic passage in parshas Shelach nicely illustrates Chazal's approach to the identification of anonymous persons in Tanach.
And Bnei Yisrael were in the desert and they found a man gathering wood on the Shabbos day... (Bamidbar 16:32)
Who was he? Tsalaphchad! Here it says "desert" and there it says " (our father died in the) desert "(Bamidbar 27). Just like "desert" there means Tsalaphchad, so "desert" here means Tsalaphchad.
R. Yehuda Ben B'seira said: Akiva, you are destined to account for this… If the Holy One Blessed be He hid this matter, do you reveal it? But who was he (the gatherer)? >From the "ma'apilim", ones who pushed forth to enter the Land (after being commanded not to do so). It says : "and they pushed forth to go up to the top of the mountain" (Sifri Shelach 7).
Similarly, "and the anger of Hashem was kindled against them (Miriam and Aharon) and he went away (Bamidbar 12)". This teaches us that Aharon also became a leper - the words of R. Akiva. R. Yehuda Ben Baseira said to him: "Akiva, in whatever manner, you will come to account for this. If as you say, the Torah hid it and you reveal it. If not, you speak slander of that tsadik. But it says "kindled against them"? (Aharon suffered) disapproval only (Shabbos 96b-97a).
While a modern historian views the Bible, as a haphazard and fragmentary historical record, the Sages saw it as an exquisitely crafted and omni-significant document. As such, a question arises: "why are certain individuals identified by name and others remain anonymous in its narratives?"
The search for significance of every detail led to certain generalizations and shortcuts to interpretation and these were transmitted by tradition form generation to generation. One may think of them as "rules of thumb" that one encounters in any discipline or category of thought. As R. Z. H. Chajes explains in Ch. 22 of Mevo Hatalmud, certain books of the Tanach, such as, for example, the Song of Songs, were assumed to operate under the assumption that all references in them are to be interpreted in a positive light. In Chapter 20, R. Chajes explains another such rule - that all references to known sinner are to be interpreted to his detriment while all references to a tsadik must be interpreted to his benefit. This certainly explains R. Yehuda b. Baseira's objection to R. Akiva's interpretation regarding Aharon. Why, however, does he object to a negative characterization of Tsalaphchad?
It appears that the same principle operates in that case as well. Having been told by his daughters that Tsalaphchad was really a tsadik, that is that his sin was of private nature and not one of the great rebellions of the generation of the dessert, we must not ascribe to him a greater sin than that, such as profanation of the Shabbos.
Gur Arye in 27:3 suggests that the issue was somewhat different. He posits that had the sin of Tsalaphchad been profanation of Shabbos, it would have been fully described. Since it was not, R. Yehuda assumes that it was a part of group failing. It is not expected that if a group sins, the names of each member in the collective transgression would be specified. He accordingly searches for an anonymous transgression and finds it to lie with the ma'apilim described nearby.
A serious student of the Midrash must be aware of these exegetical shortcuts and be on the lookout to discover and understand them. In this manner, the words of Chazal, as well as their disagreements, can become more intelligible and transparent, revealing the centuries of application of various exegetical approaches and the traditions that undergirds them.
1 Rashi in Shabbos 97a seems to derive it from the fact that Tsalaphchad's daughter mentioned his sin at all, something that she certainly did not have too volunteer, suggesting that while a sin, it was not of the gravity of desecrating the Shabbos. He follows the same line of reasoning in his commentary to 27:3, only the sin that they would not have mentioned is "and he was in midst of the group who stood against Hashem in the congregation of Korach" and not among the complainers. The lesser sin is attempting to enter the Land against Hashem's warning. The Netsiv in his Chumash commentary as complemented by his commentary to our passage in the Sifri, explains that the ma'apilim knew that they will not succeed but they longed to die in the Land of Israel. Nevertheless, they were driven back and died in the desert, outside of the Land. This is what the daughters of Tslaphchad refer to by saying that he died in the desert.
2 The Tosafos questions why R. Yehuda ben Baseira was not willing to "learn", that is to accept, R. Akiva's gzeira shava. R. Tam answers that the Tannaim knew that there is only a specific number of such derivations and R. Yehuda already possessed that number of gzeiras shava's and, therefore could not accept this one from R. Akiva without having to discount one of his own. Some Acahronim, however, point out that there exist Rabbinic derivations in the form of gzeirah shava and this one was apparently such a one. See Netsiv in the commentary to our passage, R. Reuven Margolios in Mergalios HaYam to Sanhedrin p. 16, Azriel Shimshon Hirsh in Mesores MiSinai, p. 152
3 See Shir Hashirim R. on the verse "he brought me to the banqueting house" to the effect that R. Meir who had expounded the words as meaning that the people of Israel had confessed that they were dominated by the impulse of evil, was reproached by R. Judah on the ground that the Song of Songs was always to be interpreted eulogistically. Similarly, when R. Meir sought to interpret the passage "while the King sits at the Table, my spikenard send out its smell" as referring to the making of the Golden Calf, R. Judah retorted that the Songs of Songs was not to be interpreted disparagingly, and this principle was like a guiding light to all subsequent preachers, so that where it was possible to attach to the content of the Poem credit and praise to the people of Israel, they did not rest until they found some basis or support for that line of thought, in order that they may be make effective the principle above. (translation of J. Schachter, Student's Introduction to the Talmud, Feldheim,1960)."
R. Meir was, of course, R. Akiva's student and carried forward his traditions (Eiruvin 96). Does this suggest that R. Akiva and R. Meir did not believe in or did not value interpretative shortcuts? That hardly seems credible for we find no explicit disagreements about them; neither would it make sense to fault them for not employing exegetical rules to which they did not subscribe. Rather, it seems reasonable that "local" explanation must be sought for every circumstance in which they did not use these rules.