The Gemora (Kiddushin 57a) notes that some opinions do not expound the word “es.” This would be in accordance with the following braisa: Shimon Ha’amsoni, and others say that it was Nechemia Ha’amsoni, would expound on every word es that was written in the Torah. (This means that he would teach what the word es was coming to include.) When he reached the verse that states you shall revere es Hashem your G-d, he stopped expounding on the word es. Shimon Ha’amsoni felt that it is impossible to equate the reverence of Hashem to anything else, so he retracted from all of his previous interpretations of the word es. When questioned by his students what would happen to all the words es that he had expounded upon previously, Shimon Ha’amsoni replied, “Just as I received reward for expounding on those words, I will receive reward for retracting my interpretations. Rabbi Akiva arrived later and expounded the verse to mean you shall revere es Hashem your G-d, to include Torah scholars. Just like one is obligated to revere Hashem, so too, one must revere Torah scholars.
The Pardes Yosef (Vayechi) explains Rabbi Akiva by citing the Gemora in Nedarim, which states: Rav Yehudah said in the name of Rav: What does the verse mean when it says: Who is the man who is wise and can understand this? This (the reason for the destruction of the Second Temple) was asked to scholars and prophets and they could not explain it, until Hashem explained it Himself, as it says: And Hashem said that it is because they left my Torah. Isn’t the phrase “and they did not listen to My voice” the same as the phrase “and they did not go in its ways”? Rav Yehudah explains in the name of Rav: This means that they did not recite a blessing before learning Torah.
Rabbi Akiva was saying: The word es is including the Torah scholars. The Holy One, Blessed be He said: it is because they left “es” my Torah. They left that which was included from the word es, for they were not honoring the Torah scholars.
However, it can be asked that the Torah scholars should have been mochel the respect that they deserved!? We have learned that if a Torah scholar is mochel on the honor due to him, it is valid!
This is why Hashem continued with the verse, it is because they left my Torah. Hashem is saying: The Torah is Mine and the Torah scholar cannot be mochel. Why is the Torah Mine? It is because Klal Yisroel did not recite the blessing before learning Torah. The Gemora Brochos asks: It is written: The entire world belongs to Hashem. But it is also written: And the land was given to the people!? The Gemora answers: It depends if they recite a blessing first or not. Since they didn’t recite the blessing before learning Torah, it is regarded as Hashem’s Torah, and the Torah scholars could not be mochel on the obligation to honor the Torah.