It is written in Gemara Shabbos (88a); R' Elazar said: When Bnei Yisroel declared in Sinai “We will do” before “We will hear,” a Bas Kol emerged and said: “Who revealed to my children this secret that the angels (malachim) use?” As it is written: “Bless Hashem, His angels, the strong ones, which carry out His word, to hear the voice of His word” (Tehillim 103/20). First, the malachim carry out His word, and after that they hear His voice.
Zera Shimshon asks how is it possible to "carry out His words" before they hear what those words actually are? What exactly are they carrying out?
Secondly, why is doing only after hearing considered substandard and what is so great about doing before hearing?
The Gemara a few lines later relates the following incident: A heretic once saw Rava so deeply immersed in a sugiya, that even though Rava stuck his fingers beneath his leg, and was squeezing them so hard his fingers were spurting blood, Rava did not notice! The heretic said to Rava: You impulsive nation! You used your mouth before your ears, and you are continuing with your impulsiveness. You should first listen and then, if you are capable of fulfilling the commandments, accept them, and if you are not, do not accept them. Rava replied to him: Concerning us, who go with complete faith, it is written: “The perfection of the upright leads them,” (Mishei 11:3), whereas about those people who walk in deceit, it is written at the end of the same possuk: “but the distortion of the faithless destroys them.”
Zera Shimshon asks why did it bother the heretic that Rava was so immersed in his learning, and why did Rava describe his actions as "going with complete faith"?
Zera Shimshon explains in light of a Medrash and a Mishna in Pirkei Avos.
The Medrash
The Medrash (Yalkut Shemoni remez 587) quotes the possuk (Yechzkal 20/11); "And I gave them My statutes, and I made known to them My ordinances, which, if a person performs (yaaseh), he shall live through them" The Medrash comments on the wording of this phrase, "if a person performs" and not “if Yisroel, Cohan, or Levi performs”, implies that any person, even a non-Jew, who immerses himself in Torah learning is on the same level as the Kohen Gadol. However, the Medrash concludes that he receives less reward for his learning than the Yisroel, Cohan, or Levi since he is not commanded to learn, and learns only for his own personal desire.
From this Medrash we learn the usage of the verb "laasos" in any of its forms, like yaaseh, oiseh, or naaseh connotes “to perform a mitzvah and to receive only minimal reward”.
Pirkei Avos
It is written in Pirkei Avos (perek 1/3). Antignos of Socho received the tradition from Shimon Hatzadik. He would say: “Do not be as servants, who serve their master for the sake of reward. Rather, be as servants who serve their master not for the sake of reward. And the fear of Heaven should be upon you.” The Avos D'Rebbi Nassan explains that the Tzeddukim and Baitussim went astray because of this teaching of Antignos of Socho. They could not grasp that the ultimate level of serving Hashem is only to glorify Hashem's name and not for personal gain.
Meaning, Antignos of Socho teaches us that the highest level of serving Hashem is to serve Hashem without any anticipation of compensation and the Tzeddukim and the Baitussim could not accept this.
According to this we can explain when Bnei Yisroel said, “We will do” (naaseh - a form of oiseh) they did not mean to say they will do the mitzvos even before they hear what they are. Rather, they meant to say they love, fear Hashem and want to serve Hashem to such a degree that they were willing to accept (naaseh) Hashem's mitzvos upon themselves as if they weren't commanded and forgo complete compensation from Hashem. That is how much Bnei Yisroel wanted to serve Hashem.
This is the secret of the angels' exemplary service to Hashem; they don't ask or anticipate any reward for what they do. They only do it to sanctify Hashem's name.
The heretic was so annoyed and bothered by Rava's learning with such intensity that he even harmed himself because a person who serves Hashem with no regard for his personal benefit and pleasure is the complete antitheses of the heretic's false religious belief.
