The pasuk states that every Egyptian drowned in the sea, there did not remain "עד אחד" - "Not a one." What is the Torah adding by saying these words? It could have just as well left these words out. Is the Torah teaching us something more?

     Yes, answers R' Moshe Chaim Ephraim zt”l of Sedlikov, based on the words in אז ישיר that the Jews sang after their miracle: “ה’ איש מלחמה ה’ שמו”. Rashi explains that Hashem's weaponry with which he battles the enemy is with His Holy Name. Just as we find in the Zohar that Dovid defeated the giant Goliath by employing the words of Krias Shema, "שמע ישראל ה’ אלקינו ה’ אחד", which denotes the unique Oneness of Hashem's Name. It is this Name that protects and saves us from harm.

     When we recite Shema, the letter "ע" from the first word and the letter "ד" from the last word, should be drawn out with intense devotion, as prescribed in halacha. Thus, the Torah is telling us that when Hashem rendered the mighty Egyptian army harmless, destroying them in the depths of the sea, it was done through "עד אחד" - the all powerful and omnipotent Name of Hashem, which is clearly denoted in the first pasuk of Shema.