Who was first to descend into the sea? In the Midrash, Rebbi Meir says that it was Shevet Binyamin (whereupon Bnei Yehudah took offense and tried to stop them); whereas according to Rebbi Yehudah, it was Nachshon ben Aminadav of Shevet Yehudah who went in first. What is behind these opinions?
Maharal (Gevuros Hashem, beg. Ch. 42, p. 158): a. Rebbi Meir - Binyamin was the youngest and last (Acharon) of the Shevatim. "Yam" as a direction means west, also called "Achor." 1 Because Binyamin was most closely associated with the "Yam;" it was appropriate that they descend first into the sea - despite that Yehudah is generally first. 2 Chazal say that Bnei Yehudah 'threw stones at' Binyamin for doing so - but nevertheless Binyamin prevailed; as they deserved to go first in essence, whereas Yehudah's claim to go first was due to their stature in general. 3 b. Rebbi Yehudah - Of all the Shevatim, only Yehudah wanted to go into the sea, as in the verse, "Yehudah became his holy [portion]" (Tehilim 114:2). Hashem's Name is found within Yehudah's name; 4 and the very name Yehudah means giving thanks to Hashem (Bereishis 29:35).
As in Yeshayah 9:11. In the Degalim of the Midbar as well (Bamidbar 2:22), Binyamin was positioned to the west (Yamah).
Yehudah was positioned in the east (Kedmah).
Binyamin merited that the Shechinah reside in his portion (as the Shechinah is in the west); whereas Yehudah merited the monarchy (the king goes first). For more about Binyamin being last, the completion of the Shevatim, refer to Bereishis 35:18:2.2, Bereishis 35:17:2.1, and Bereishis 35:18:2.1:1.
That is why Yehudah merited the monarchy; as he who glorifies the Name of Hashem will be granted a great name himself. Kidush Hashem means demonstrating that Hashem is above (Nivdal from) everything else; so too is the king above all of his subjects. (For more on Yehudah's greatness when he sanctified Hashem's Name by admitting his role with Tamar, refer to Bereishis 38:26:1:1* and Bereishis 38:26:1.3:2. For more about Yehudah's monarchy in the context of Birkos Yaakov, refer to Bereishis 49:8:151.1 .)
Why does the verse specify "at their right and at their left;" instead of merely saying, 'on this side and on that'?
Maharal (Gevuros Hashem Ch. 42, p. 159): Chazal interpret - The sea split in the merit of the Torah, given by [Hashem's] Right Hand, 1 and in the merit of Tefilin, worn on the left arm. 2 As Maharal explains, the waters of nature (Chomer) were pushed aside by holy and transcendent (Nivdal) matters, i.e. Torah and Mitzvos 3 - and the water stood tall at attention.
