This explains very nicely the remez inherent in the passuk: "ולמען תספר באזני בנך ובן בנך את אשר התעללתי במצרים ואת אותותי אשר שמתי בם"—and so that you may relate in the ears of your son and your son’s son that I made a mockery of Mitzrayim and My miraculous signs that I placed among them. We will refer to what the Bnei Yissaschar writes in the sefer Maggid Ta’alumah on Maseches Berachos (2a), and what is brought down in the sefer Kol Eliyahu (Yoma 202) in the name of the Gra. They address the words "ודברת בם" Krias Shema, meaning “you should speak of them.” They assert that the term "בם" alludes to Torah she’b’chsav and Torah she’b’al peh as follows: Torah she’b’chsav begins with the letter “beis” of "בראשית ברא אלקים", while Torah she’b’al peh begins with the letter “mem” of (Berachos 2a): "מאימתי קורין את שמע בערבין". Likewise, this is the remez in our passuk: "ולמען תספר באזני בנך" refers to Torah she’b’al peh which is transmitted from a father’s mouth to his child’s ear; "ואת אותותי אשר שמתי בם" connects Torah she’b’chsav and Torah she’b’al peh via the term ב"ם, which is formed by the first letters of ב'ראשית and מ'אימתי.
The Remarkable Relationship between the Plague of “Arbeh” and the Plague of “Barad”
We can now rejoice, for we have succeeded in shedding some light on the subject. We can now begin to comprehend why HKB”H arranged for the plague of “arbeh” to complete the devastation of the plague of “barad.” As explained, the “ten makkos” align with the “ten utterances” in reverse order. Thus, the plague of “barad” aligns with the fourth utterance (Bereishis 1, 9): "ויאמר אלקים יקוו המים מתחת השמים אל מקום אחד ותראה היבשה ויהי כן"—G-d said, “Let the waters be gathered beneath the heavens into one area, and let the dry land appear.” And it was so. Similarly, the plague of “arbeh” aligns with the third utterance: “Let there be a firmament between the waters.”
Now, in his commentary, Rashi asks (Bereishis 1, 7): Why does it not say "כי טוב" on the second day (as it does on the other days of creation)? Because the work of the creation of the water was not completed until the third day, although He began it on the second day. And something which is incomplete has not yet achieved its full potential and goodness. Accordingly, the utterance “Let the waters be gathered beneath the heavens into one area” is the completion of the utterance “Let there be a firmament between the waters.”
With this in mind, let us suggest an interpretation of the phenomenal fourth utterance: “Let the waters be gathered beneath the heavens into one area, and let the dry land appear.” This utterance alludes to the fact that HKB”H covered up and concealed Torah she’b’al peh beneath dry land, so that it would be inaccessible to the nations of the world. Only Yisrael, by means of toiling and dedicating themselves to the study of Torah, are able to uncover it and reveal its treasures. This is the implication of the teaching in the Mishnah (Avos 5, 22): "הפוך בה והפוך בה דכולה בה"—delve into (turn) it over and over again, for it contains everything.
This explains magnificently the relationship between the plague of “barad” and the plague of “arbeh”; they complemented each other. As explained, these two makkos align with the third and fourth utterances of creation— "יהי רקיע בתוך המים" and "יקוו המים מתחת השמים אל מקום אחד" –that complemented one another. Hence, it is not for naught that the Torah emphasizes the fact that the locusts consumed all of the vegetation and fruits of the tree that remained after the hail: י העץ אשר הותיר הברד""ויאכל את כל עשב הארץ ואת כל פר.
