Sefer Devarim – the book of Moshe’s speeches (literally meaning the “book of words”) – opens:
אֵלֶּה הַדְּבָרִים אֲשֶׁר דִּבֶּר מֹשֶׁה אֶל-כָּל-יִשְׂרָאֵל
The Midrash Tanchuma asks how it is that Moshe went from being a man in Sefer Shmos of few words, who could barely speak, to a man of many words, and an orator of such eloquence…how did he get from לֹא אִישׁ דְּבָרִים אָנֹכִי to אֵלֶּה הַדְּבָרִים ?
The Midrash Rabbah, quotes Mishlei 15:4 to help answer this question: Marpeh lashon eitz chaim = “The one that heals the tongue is the tree of life.”
מָה אָהַבְתִּי תוֹרָתֶךָ כָּל הַיּוֹם הִיא שִׂיחָתִי
How do we fulfill this goal of having our entire day filled with words of Torah? If we’re not sitting and learning the entire day, how can we make Torah our day-long conversation?
These ideas came to mind not only with Tish’a B’Av around the corner, but also because Daniella’s matzeivah was recently erected, and on it is the perfectly fitting passuk of:
מָה אָהַבְתִּי תוֹרָתֶךָ כָּל הַיּוֹם הִיא שִׂיחָתִי
This passuk was chosen for Daniella’s kever and so magnificently encapsulates Daniella’s way of approaching her day and the world – always speaking and interacting in the ways of Torah, with kind words and no judgments.
Finally, Rav Ozer Glickman shlita writes on the original question posed about Moshe’s “transformation”, that the Rambam in the beginning of Hilchos Teffila explains that the liturgy chosen was the response to the dispersion of Jews throughout the world, and the lost ability to express themselves in a single, unified language. We lost our ability to articulate our praise and affection for Hashem and our requests of Him, on a personal and communal level. (Please G-d, our unified teffila, particularly of matir asurim, should be answered for the IDF soldier captured this morning: Hadar ben Chedvah Leah)
The more Torah and Torah values we study and personify, the more significance our prayers will have. Just as a person cannot pick up a musical instrument and produce beautiful music without practice, and just as Moshe needed Torah and closeness to Hashem to learn to produce the beautiful words of Sefer Devarim, so too is Torah the key to our refined speech and d’veikus, both with Hashem and our fellow man.