Why are there so many aspects of the Torah non-explicit and require rabbinic interpretation?  Is this due to our inadequacy to understand and transmit the truths of the Torah or is it by design?

The Gemara on amud aleph discusses the concept of Hashem taking pride in his sons winning against him. Moshe somehow “convinces” Hashem to relent from destroying the Jewish people after the sin of the Golden Calf. This idiom is also used by Gemara Bava Metzia 59b when describing the outcome of the machlokes between Rabbi Eliezer and the Sages in the great Oven of Achnai debate. Despite Rabbi Eliezer summoning various miracles and signs from heaven to show his position to be correct, Rabbi Yehoshua declared that we follow the majority and the Torah is no longer Heaven. That means, no miracle or sign or prophecy can override the rabbinic deliberations and the subjective nature of the majority rule. G-d’s reaction then was also described with the same idiom, “my children have won over me”, as we might imagine how a proud father feels when his son wins him in a game of chess. It is notable that the same language is used to describe Hashem’s “reaction” in both of these cases, indicating a similarity. The Shittah Mekubetzes in the name of Rabbenu Chananel (Bava Metzia 59b) explicitly compares these two situations, but does not elaborate. 

The question for us is what is the link between these two events? Furthermore, the victories are also different in character. In the Oven of Achnai, the rule of subjective halakhic perception of the majority wins over the actual “heavenly truth”. In the case of the Golden Calf, Moshe caused a victory of the manifestation of G-d’s mercy over G-d’s judgment, Middas HaRachamim over Middas Hadin.

In order to understand this, it is necessary to understand a concept that we find in the Oral Torah and the Written Torah. The Written Torah is the divine word and a strict expression of the divine will, so to speak the blueprint and plans.  As we know about plans and blueprints, reality often is not quite as smooth. The Oral Torah is a dynamic combination of the oral tradition from Moshe and the rabbinic derivations, reasoning, and logic, as it encounters the divine and makes it work in the human world. Thus, Rav Tzadok (Pri Tzaddik Shavuous 7:6 quoting Zohar III:80b) considers the Written Torah to be representative of Middas HaDin and the Oral Torah representative of Middas HaRachamim. 

As was noted in other psychology of the Daf discussions (see Psychology of the Daf Pesachim 81), invariably the Torah Sheba’al Peh and rabbinic interpretations of the verses are more lenient than the strict literal meanings. One day I’ll make an extensive list but here are a few: 

• Eye for an eye (Bava Kama 83b) 
• 40 lashes stated in the verse but actually only 39 (Makkos 22) 
• The Prohibition of Piggul. The literal verse invalidates a sacrifice and makes the owner RETROACTIVELY liable for punishment based on the action of someone eating from the sacrifice beyond its correct time (Vayikra 7:18), but the oral law only creates future liability based on past actions (see Rashi Op. Cit). 
• Do not burn a fire in your dwelling on the sabbath (Vayikra 35:3) which implies a prohibition to merely having a fire burning though we of course allow a fire left on
• You shall cut her hand off (Devarim 25:12), which is understood as monetary compensation instead of actual corporal retribution (Bava Kamma 28).
• If anyone who has become unclean fails to cleanse himself, that person shall be cut off from the congregation, for he has defiled the LORD’s sanctuary (Bamidbar 19:20). The actual prohibition is not on passively remaining impure but rather upon entering the Temple or Courtyard while impure (Shavous 16b)

We can now understand the connection. By the Golden Calf, Moshe recruited the Middas HaRachamim to override the Middas Hadin. In the Oven of Achnai dispute, Rav Yehoshua’s stand against all the miraculous interventions was a victory of Torah Sheba’al Peh and the Torah not being in Heaven. When the midrashic literature refers to Man “winning” over G-d, it is about Man taking ownership of how the Torah needs to be applied in this world once it becomes of this world (See Maharal Be’er HaGolah 4:4 who alludes to this.)

Returning to the father-son archetype, as parents we encounter this experience as well. We have to learn when to let our children own their lives and when to not merely let them win, but even rejoice in their success, regardless of our plans for them.