In the beginning of Devarim 29, Moshe does a wrap up of what the Jews went through on their journey through the desert:
וַיִּקְרָא מֹשֶׁה אֶל-כָּל-יִשְׂרָאֵל, וַיֹּאמֶר אֲלֵהֶם: אַתֶּם רְאִיתֶם, אֵת כָּל-אֲשֶׁר עָשָׂה יְהוָה לְעֵינֵיכֶם בְּאֶרֶץ מִצְרַיִם, לְפַרְעֹה וּלְכָל-עֲבָדָיו, וּלְכָל-אַרְצוֹ. הַמַּסּוֹת, הַגְּדֹלֹת, אֲשֶׁר רָאוּ, עֵינֶיךָ–הָאֹתֹת וְהַמֹּפְתִים הַגְּדֹלִים, הָהֵם. וְלֹא-נָתַן יְהוָה לָכֶם לֵב לָדַעַת, וְעֵינַיִם לִרְאוֹת וְאָזְנַיִם לִשְׁמֹעַ, עַד, הַיּוֹם הַזֶּה – And Moshe called all the Jews, and said to them: “You saw all that Hashem did in Egypt, with your own eyes, to Paroh, his servants, and his land. The great miracles and signs you saw. And Hashem didn’t give you a heart to understand, eyes to see, nor ears to hear, until this day. (29:1-3)
Rashi elaborates that עַד הַיּוֹם הַזֶּה has an undercurrent. In Devarim 31, Moshe writes the Torah in the form we have it, and give it to the Levi’im, who entrusted with the task of safeguarding and teaching Torah. Rashi says that עַד הַיּוֹם הַזֶּה refers to that event. What was the appraisal of their faculties, that on “this day”, Moshe praised the Jews?
Rash explains how when Moshe gave the Torah to the Levi’im, the Jews protested their being singled out for keeping it, with the worry that perhaps Levi would claim the Torah for their own, and exclude the other tribes. When Moshe saw this, he saw the the Torah was precious to them, and said עַד הַיּוֹם הַזֶּה.
R’ Leib Salomon has great difficulty with this. What was the protest going to be, exactly? It couldnt be that they were worried that perhaps the Levi’im would keep the whole Torah for themselves, how could they? Who would give ma’aser, among many other things?
R’ Matisyahu Salomon explains that the Jews were not worried about the Levi’im laying an exclusive claim to mitzvah performance, but rather, the capacity to be a Torah scholar, talmud Torah. When Moshe heard this, he understood how much the Torah meant to them.
R’ Matisyahu points out that “The great miracles and signs you saw” were not enough to persuade Moshe that they had לֵב לָדַעַת, וְעֵינַיִם לִרְאוֹת וְאָזְנַיִם לִשְׁמֹעַ – it was exclusively their desire and passion for Talmud Torah that precipitated this realisation.
Seeing miracles isn’t what makes someone a true servant of Hashem, it is the struggle, the slog, that comes with learning Torah that a Jew has his heart, eyes and ears.