ואמרת אליו ה' אלהי העברים נקרא עלינו למה קורא אותם עברים? על שום שעברו ים.
(8) They said to him, “Tell us, you who have brought this misfortune upon us, what is your business? Where have you come from? What is your country, and of what people are you?” (9) “I am a Ivri,” he replied. “I worship the LORD, the God of Heaven, who made both sea and land.”
The tribes of Moab—trembling grips them;
All the dwellers in Canaan are aghast.
(16) Terror and dread descend upon them;
Through the might of Your arm they are still as stone—
Till Your people cross over, יהוה,
Till Your people cross whom You have ransomed.
(17) You will bring them and plant them in Your own mountain,
The place You made to dwell in, יהוה,
The sanctuary, O my lord, which Your hands established.
(18) יהוה will reign for ever and ever! (19) For the horses of Pharaoh, with his chariots and riders, went into the sea; and יהוה turned back on them the waters of the sea; but the Israelites marched on dry ground in the midst of the sea.

כי בא סוס פרעה ברכבו ובפרשיו אמר ר''א (אבן עזרא על שמות ט״ו:י״ט) שגם זה מן השירה, כי היו משוררים ואומרים כי בא סוס פרעה ברכבו ובפרשיו בים וישב עליהם את מי הים בעוד בני ישראל הולכים ביבשה בתוך הים, והוא נס בתוך נס...
FOR THE HORSES OF PHARAOH WENT IN WITH HIS CHARIOTS AND WITH HIS HORSEMEN. Rabbi Abraham ibn Ezra said that this verse is also part of the Song, for Moses and the children of Israel were singing and saying: For the horses of Pharaoh went in with his chariots and with his horsemen into the sea, and the Eternal brought back the waters of the sea upon them while the children of Israel were walking on dry land in the midst of the sea, this being a miracle within a miracle.
At the end of the road, after all is said and done, there is special mention of a unique wonder. The Children of Israel walked on land in the midst of the sea, which was a miracle within a miracle.
Miracles occur within the natural realm. Something opposes our existence, and the Creator performs miracles for us and saves us from it. But that our very existence should be within a miraculous realm and not integrated with the natural realm is beyond the standard classification of miracles.
In our minds, a miracle means being rescued in a given situation. We live in a very dangerous world and there is much hostility against us...in this concept of miracles, each rescue may be deemed another miracle.
But not upon such a miracle do we exist. Rather, the very bases of our existence is miraculous. We exist in a realm that has no place for us altogether. This means that from the aspect of the realm we live in, we do not exist. But we nonetheless exist.
Now, there are two options. The sea could split causing the place to cease being the sea. This would have been a one-time miracle. We now have a place, and it is accessible to anyone in the world. True, it became a place miraculously - the sea had split - but it is now just like any other place.
But this is not what happened. The place remained the sea, and there itself a form of existence was established for us, exclusively.
Our form oof existence is within a realm that considers our existence impossible, and to reiterate, this means that from its aspect, we do not exist. There is no existence in the sea. If someone exists there, it must not be the sea but a form of land. A place that is integrally a sea cannot sustain any human existence. It is a place of existence only for us.
...this fearsome mystery is the miracle within miracle that was revealed at the Splitting of the Sea. To exist miraculously in a system where existence is impossible is a miracle within a miracle.
רַבִּי יְהוּדָה אוֹמֵר כָּל הָעוֹלָם כֻּלּוֹ מֵעֵבֶר אֶחָד וְהוּא מֵעֵבֶר אֶחָד.
רַבִּי נְחֶמְיָה אָמַר שֶׁהוּא מִבְּנֵי בָּנָיו שֶׁל עֵבֶר.
וְרַבָּנָן אָמְרֵי שֶׁהוּא מֵעֵבֶר הַנָּהָר, וְשֶׁהוּא מֵשִׂיחַ בִּלְשׁוֹן עִבְרִי.
We are his descendants, and this is what happened to us at the Splitting of the Sea. We became Crossers/ivrim - we crossed the river, we crossed the Sea of Reeds. We crossed to a place that is inherently on the other side, or in other words, to a place where no one else can reach.
(44) You have screened Yourself off with a cloud, That no prayer may pass through.
Apparently, the Pillar of Cloud came to make it dark. But why was it necessary? Moreover, it is well known from the sages and implied in the verses that the Pillar of Cloud came to provide light, not to darken:
רבי שמעון בן יוסי אומר כל ארבעים שנה שהיו ישראל במדבר לא נצרך אחד מהם לא לאור החמה ביום ולא לאור הלבנה בלילה, אלא הֶאֱדִים - היו יודעין ששקעה החמה; הלבין - היו יודעים שזרחה החמה, ומסתכל בחביות ויודע מה שבתוכו, בטפיח ויודע מה שבתוכו, מפני ענן השכינה שביניהם.
The pillar of cloud shifted from in front of them and took up a place behind them, and it came between the army of the Egyptians and the army of Israel. Thus there was the cloud with the darkness, and it cast a spell upon the night, so that the one could not come near the other all through the night.
ויבוא בין מחנה מצרים ובין מחנה ישראל ויהי הענן והחשך הענן על ישראל והחשך על המצריים. מגיד הכתוב שהיו ישראל באורה ומצרים באפלה. וכן במצרים לא ראו איש את אחיו. וכן אתה מוצא לעתיד לבוא קומי אורי כי בא אורך מפני מה כי הנה החשך יכסה ארץ וגו'. ולא עוד אלא כל שהוא נתון באפלה רואה מה שהוא נתון באורה. מצרים שהיו נתונים באפלה רואין את ישראל נתונין באורה ואוכלין ושותין ושמחים והיו מזרקין בהם חצים ואבני בליסטראות והענן (מקבלן מהן) [מגין עליהם].
This explains the Pillar of Cloud. Its purpose was truly to provide light. But light is unfeasible without darkening the existing light. If the existing light is perceived as light, the other light cannot be seen. Both lights cannot exist concurrently. They are paradoxical; they are opposites.
לדוד ה' אורי וישעי ממי אירא...בנוהג שבעולם אדם מדליק את הנר בפלטין שלו. שמא יכול לומר פלוני שהוא אוהבי ישתמש לאורו ופלוני שהוא שונאי אל ישתמש לאורו. אלא הכל משתמשין לאורו. אבל הקב"ה אינו כן אלא והיה אור ישראל וגו'. בני יראו ושונאי אל יראו. וכבר עשה דוגמא זו במצרים (שמות י כג) ולא ראו איש את אחיו וגו' ולכל בני ישראל היה אור. (שם יג כא) וה' הולך לפניהם יומם. ואומר (שם יד כ) ויאר את הלילה ויהי הענן והחושך.