Taken from his volume on Shemos “And There Was Light” published by Targum Press.

(24:7) … they said "all that G-d has spoken we will do and hear" - Na'aseh V'Nishmah.

The Midrash is well known (Talmud Shabbos 88) that a Heavenly voice proclaimed: "who revealed to My children this secret which the ministering Angels use…?"

We must note that twice before (19:8 and 24:3), Bnei Yisrael had responded only with "we will do!" Between verses 3 and 7 in Chapter 24, Moshe writes: "all the words of G-d" and reads to the people the "Book of the Covenant" after which they finally say the unique double expression. Apparently, the change from oral speech to writing is the key to this change in response, and it must be analyzed and understood.

The Midrash Rabbah (Devorim 3:12) and the Yerushalmi (Shekolim 1:1) inform us mystically that the Torah given to Moshe was "black fire engraved upon white fire." Thus we, too, write the Torah with black ink upon white klaf.
To comprehend this mystery, Rav Levi Yitzchak of Berdichev is quoted in Imrei Tzaddikim explaining the Midrashic comment (Mechilta, P. B'Shalach) that even the maidservants saw, at the splitting of the sea (Yam Suf) what Yechezkel and the other prophets never did. He notes the Midrash (Rabbah Vayikra 13:3) that G-d exclaims: "a new Torah (Torah Chadash) from Me will go forth, renewed Torah (Chadosh Torah) will go forth from Me!"

He asks the obvious question: Does this not contradict one of the 13 Principles, that the Torah will never be changed or abrogated? He explains: "Why does a Torah become disqualified if a letter merely touches, ever so slightly, an adjoining one?" This fact proves that the empty spaces - the "white" - is also, in fact, letters of the Torah, but we unfortunately are not trained to read them. In the future G-d will reveal to us that secret too. This is the "new Torah" that will some day be revealed to us! This special writing was revealed at the Sea to all present, but not even to the prophets in later years, thus, clarifying the Midrash about the maidservants.

This explains the Talmudic law that, one who sees a Torah rent to pieces, must tear "kria" twice. For, he rends his garment over the visible black writing and over the un-deciphered "white writing" which we will someday understand.
Kabbalistically, we might explain that the "white (fire) letters" represent the very source of Torah in Heaven (before it came down to us) in its purest real essence and which is beyond the ability of physical man in this world to grasp. G-d "contracted" Tzimtzum- His will and Mitsvos into visible "black" letters so that part of Torah could be understood by physical men in this physical world. Only in our future higher existence will be attain understanding of this hidden Torah which will be for us a "new" Torah."

Thus, we may suggest that when great Talmidei Chachamim attained new dimensions of Torah understanding not perceived before, the source was hidden in the "white letters" and revealed to them as a reward for their diligence and striving in Torah pursuit. This would perfectly explain why their thoughts are called Chadushei Torah.

Thus, when King Shlomo writes in his holy Shir HaShirim (2:5) "Samchuni B’ashishos" - sustain me with "ashishos" (a difficult term that has been translated many different ways), the Midrash Rabbah on that verse explains: "sustain me with two fires (aish), the fire of above and the fire of below, i.e. the "white" fire of Heaven and the "black" fire we read on Earth.

Since one may catch glimpses of this hidden Torah by great diligence, we may now understand the comment of Rav Mana (Yerushalmi, Pea 1:1) on the verse in D'vorim (32:47): "for it is not an empty thing (word) for you"; "and if it is empty, it is from you (your fault). Why? Because you do not tire yourself in Torah" i.e. if we were truly diligent, the empty spaces (the white letters) would reveal some of their secrets as they do to great scholars many times in their lifetimes.

We may now also understand in a new dimension the two Brachos we recite for Torah learning every morning. The first is for the study of the visible Torah La-asok B’divrei Torah as we read it. The second one seems difficult. Our tradition claims that G-d offered the Torah to several (all) other nations who refused it! How can we say that "He chose us of all peoples and gave us His Torah?" We must surely presume, however, that He would have given them only the visible written Torah had they accepted. For us, He gave "HIS" Torah, the secret hidden Torah that only great scholars gain glimpses of in their dedicated pursuit of its mysteries. Hence, the Halachah that decided we should say both is a perfect solution. In fact, the Talmud (Brachos 11) states that this second bracha is the "higher" of the two.

It is noteworthy that Rashi mentions these two fires (aish daas) in the very verse that describes how G-d arrived to give us the Torah and after the futile attempt to offer it to the others (Devorim 33:2). Now we can comprehend the strange statement in the Zohar HaChadash (Shir HaShirim, p. 74) that the Torah contains 600,000 consonents, when in fact we know it has exactly 304,805! This problem intrigued many great commentators.

Answer: The Zohar also understood how to count the "white letters." Together they are 600,000! We can now finally understand the topic with which we began. When Bnei Yisrael heard the words of Moshe orally, they only conceived of laws to be studied and remembered. Thus, they responded with "we will do." Once Moshe had recorded the "Book of the Covenant" and read to them from the text, they suddenly were seized by the realization of the mysteries that were hidden in the "fires" of this Torah and added: "we will hear" (study) the text carefully. This grasp of the mystery is what evokes G-d's "admiration" as He exclaims, "who revealed to my children this mystery which only the Angels were privy to before."

Source: Rav Pinchas Friedman, in HaMachaneh HaCharedi
May 12, 5754