"Judah became holy. When Israel arrived at the sea, they fought with each other. One tribe went down to the sea first, and the sea did not dry up until they entered it. They continued to descend until they reached the bottom of the sea, as it is said: "Save me, O God!
For the waters have come up to my neck" (Psalm 69:2). It is also written: "And the children of Israel went into the midst of the sea on dry ground" (Exodus 14:22). Benjamin the Righteous went first into the sea, as it is said: "There is little Benjamin, their ruler, in the lead" (Psalm 68:28). Do not read "in the lead" [in Hebrew: "ro'dem"], but rather "into the sea" [in Hebrew: "yored yam"].
What did Nachshon ben Aminadav do? He jumped into the waves of the sea and sanctified the name of the Lord before all, and rebuked Benjamin, as it is said: "The leaders of Judah were shouting, and the rulers were with them" (Psalm 68:28). And it was under the leadership of Nachshon ben Yehudah that Israel crossed. And because he rebuked his brothers, he merited the purple robe, as it is written: "And they clothed Daniel with purple" (Daniel 5:29).
God said to him, "You rebuked your brother to sanctify My name. You shall be a ruler over your brothers." Judah truly became holy through his leadership. The sea saw that Israel was fighting each other over the sanctity of God's name.
The sea said, "What am I standing here for?" and immediately fled, as it is said: "The sea saw and fled" (Psalm 114:3). Another interpretation: The sea saw that Joseph's coffin was being lowered into it and said, "I will flee before him," as it is said: "And the sea fled before them" (Genesis 33:10). Just as the sea was a miracle for them, it shall be a miracle for you. Be like the sea and flee.
Another interpretation: The sea did not want to split because the people were rebelling. It said, "They rebel, and I will split before them," as it is said: "They were rebellious at the sea, at the Red Sea" (Psalm 106:7). And just as the sea was punished for rebelling, God rebuked it, as it is said: "He rebuked the Red Sea also, and it dried up" (Psalm 106:9). As soon as the sea saw this, it fled, as it is said: "Be ashamed, O Sidon, for the sea speaks, the stronghold of the sea, saying: I have not been in labor or given birth, I have not raised young men or brought up young women."
The sea said: I am afraid of Him because I have no protection other than Him. You, on the other hand, have raised numerous young men and brought up countless young women, yet you are not afraid of Him. (Exodus 14:29).