רתונ אל םהמ דחא
There is a machlokes in Chazal whether this passuk means not even one of the Mitzriyim survived the drowning of Yam Suf even Pharaoh perished in the sea. Others opine that up to one died but Pharaoh survived and became the king of Ninveh in which he instructed the city to do teshuva by Yona the Navi. If we look at the plague of dever we find the lashon of the passuk דחא תמ אל לארשי ינב הנקממו. Yet Chazal derive from this that one of Bnei Yisrael's died. It could very be because before in the warning of the coming plague Hashem said לארשי ינבל לכמ תומי אלו רבד. Yet when the plague actually happened the Torah did not use again the word רבד but substituted it with the number דחא instead. The change in words could cause one to think that דחא תמ אל means only one died. However in the scenario of Kerias Yam Suf it says אחד מהם לא נותר which sounds that not even one perished which makes it difficult to the opinion that Pharaoh was the only one that survived?
We want to interpret this passuk in the way of derush which has nothing to do with Pharaoh and the question of his survival. The nations of the world preach unity. In the pledge of allegiance to the American Flag I remember as a little kid we would recite with our right hand over our hearts in order to show one really means it One Nation Under G-d indivisible with liberty justice for all. Today this pledge is malarkey and meaningless every word. It might have gotten that way because you are pledging to a flag an inanimate object like an avodah zarah.עינים להם אלו וארי. If the pledge was to G-d I am not sure if that would make a difference either. At least every child in the morning would mention Hashem as being part of his vocabulary which is some accomplishment.
One nation indivisible. Am Yisrael prides themselves on their unique oneness and indivisibility. As Rashi points out on the passuk ויחן ישראל נגד ההר he writes כאיש אחד בלב אחד . Yet even Mitzrayim also claims that they have unity and this is learned from passuk ומצרים נוסע and the Egyptians were chasing after Yisrael camped at the Yam Suf. The Torah נוסע and not נוסעים. Rashi comments בלב אחד כאיש אחד . So it does look like that Yisrael does not own an monopoly under the title "one nation".
However the Avnei Nezer makes a distinction between the two verses. By Am Yisrael it first places the דחא שיא to be followed by דחא בלב and by Mitzrayim is says דחא שיאכ דחא בלב. Am Yisrael are essentially one person, breakoffs from one gigantic neshamah and therefore בלב אחד we desire the same thing. In contrast is Mitzrayim the only thing in common is the heart and desires, power, bodily pleasure, riches so they become allied with others who also seek to satiate their lusts. When they obtain what they sought after they have no qualms of stabbing their partner in the back because they were not really united at the source.
The Maharal writes that Am Yisrael epitomizes the word דחא. The formation of Yisrael as a nation appears in the letters דחא. The letter Aleph stands for Yaakov who is set apart from the twelve shevatim. The letter ches corresponds to the eight children of Rachel and Leah. The letter dalet refers to the four children from Zilpah and Bilha. We are essentially one.
This is what the passuk אחד מהם לא נותר is referring to. The goyim claim that they too possess oneness. That is only at the beginning when they join together to defeat their enemy. But at the end when their adversaries no longer exists, the אחד מהם their "oneness" לא נותר Doesn't remain. The outcry then becomes Every Man to himself! There was never loyalty to begin with.
