It is clear from the Gemara and Rashi on top of Shabbos 97 that since Rebbi Akiva learned from a Gezeirah Shavah that Tzlafchad was the Mekoshes ("Bamidbar/Bamidbar"), it can be said that the Torah wrote Tzlafchad's sin explicitly; his sin was not "covered up" by the Torah.
My question is - is this really called that the Torah did not "cover up" Tzelafchad's sin?
Even a Gezeirah Shavah is not passed down as a "finished" Drasha. True, the Mesorah says that certain words are to be used for a Gezeirah Shavah - but the Mesorah does not tell where to use those words for a Gezeirah Shavah. It can be used for another section of the Torah entirely!
The Ramban (Sefer ha'Mitzvos, Shoresh ha'Sheni) goes further and proves that the Mesorah can tells us that a Gezeirah Shavah is used to teach us 'something' about a certain Halachah - but it doesn't tell us whether the Gezeirah Shavah is from word A (which will teach us a Halachah from one section of the Torah) or from word B (which will teach a different Halachah from a different section of the Torah).
Since Rebbi Akiva had the leeway to learn the Gezeirah Shavah otherwise, why is he justified in condemning Tzlafchad based on his Gezeirah Shavah?
Could the Gemara mean to say that if the Torah makes it possible to learn a Gezeirah Shavah that will condemn Tzlafchad - it is as if the Torah consents to condemning him explicitly?
Moshe Lieber, Yerushalayim
(a) You cannot be asking that something learned from a Gezeirah Shavah, or any other Drasha, is not "explicit" enough to say that "the Torah publicized his sin." Thousands of Halachos are learned from a Drasha, yet they are treated as though they were stated openly in the Torah. As the Midrash (Bereishis Rabah 60:8) says, "Tum'ah of a Sheretz is an important law of the Torah, yet we only learn from a Ribuy that its blood is Metamei..."
We cannot guess why the Torah taught certain laws explicitly and taught others through a Ribuy. But in either case, both are considered to be "written in the Torah."
Rather, you are asking why Rebbi Akiva used his Gezeirah Shavah to teach that Tzlafchad was the Mekoshesh, if he could have vindicated Tzlafchad by learning his Gezeirah Shavah some other way. Who says that the Torah wanted him to incriminate Tzlafchad?
(b) First of all, it is not clear that every Gezeirah Shavah requires input on the part of the Doresh. The very Ramban that you cited concludes tersely, "I would add that perhaps the exact details [of how and where to apply each Gezeirah Shavah] were originally given to Moshe, but were forgotten during the days of his Aveilus" (see Temurah 16a).
Perhaps this Gezeirah Shavah was handed to Rebbi Akiva in the exact form that he quoted it. (An example of such a Gezeirah Shavah can be found in Rashi Pesachim 66a DH v'Chi.) And if not, perhaps there was no where else to apply this Gezeirah Shavah.
(c) But the truth is that your question undermines the credibility of the entire Shas.
Chazal (Kerisus 5a) tell us, "Let not a Gezeirah Shavah seem paltry in your eyes, since many important and basic laws are only learned from a Gezeirah Shavah." The Gemara there brings examples from Chayavei Kares, Sekilah and Sereifah. If we start to suggest that Gezeirah Shavah's can be applied differently - we no longer can rely on any of the teachings of Chazal!
So while it is true that the application of a Gezeirah Shavah is left to the eyes of the Tana who teaches it, nevertheless even the Tana cannot apply the Gezeirah Shavah according to his whims. Rather, there are rigid guidelines for how and when to apply a Gezeirah Shavah, and the Tana uses those guidelines to determine when to apply each one.
Thus, if Rebbi Akiva said that the Gezeirah Shavah teaches that Tzlafchad was the Mekoshesh, he must have applied all of the guidelines that he used for any other Gezeirah Shavah, including the type which teaches us when to administer the death penalty. We cannot suggest to Rebbi Akiva that he ought to have applied it differently.
(d) I would add that Rashi seems to be making an additional point here when he writes that "a Gezeirah Shavah is considered to be Mefurash (written explicitly)." He is explaining why the Gemara emphasized that it is Mefurash because it is learned from a Gezeirah Shavah .
Rashi is following his opinion (Zevachim 106b and elsewhere) that the reason we can administer Malkus or Misas Beis Din based on a Gezeirah Shavah - but not based on a Kal v'Chomer - is because what is taught through a Gezeirah Shavah is as though it has been stated explicitly in the Torah.
Rashi solves with this the age-old question of why we cannot administer Malkus or Misas Beis Din based on a Kal va'Chomer. Some say that we are afraid another Tana will find a flaw in the first Tana's Kal va'Chomer (Halichos Olam 4:12). But that is hard to accept; after all, the same can be said about a Gezeirah Shavah (as you asked), or any other Limud! Others say (see Maharsha to Sanhedrin 64b) that perhaps the sinner deserved a harsher punishment based on the Kal va'Chomer, and therefore we have no right to administer a weaker punishment in its stead. But the Gemara tells us that when two groups of people who are Chayavei Misas Beis Din become mixed with each other, we are bidden to administer the less harsh of the two deaths to all of the criminals.
Rashi in Zevachim is answering that we can only punish for a sin that is written explicitly in the Torah. If it is learned from logic alone, we cannot administer a bodily punishment. (This is not dissimilar to the rule regarding Misas Beis Din, "Ein Onshin Ela Im Ken Mazhirin"; all aspects of the transgression must be written explicitly in the Torah.) Once we learn a Gezeirah Shavah, that word in the Torah which was used for the Gezeirah Shavah is actually telling us the Halachah involved. Hence, it is written right there in the Torah.
In the case of Tzlafchad, had his sin been learned from a Kal va'Chomer, and not alluded to by any word in the Torah - Rebbi Akiva would have been wrong to publicize his sin. The Torah did not write anything about it, so why should he publicize it (even if it is true!). But now that it is a Gezeirah Shavah, the Torah actually did write a word about it, so why shouldn't Rebbi Akiva discuss it openly?
Best regards,
Mordecai Kornfeld