Why does it say "ba'Yam Darkecha"?
Radak: The sea split due to Your command, and Yisrael passed through.
What does "u'Shvilcha b'Mayim Rabim" add?
Radak: The matter is repeated in different words.
Malbim: "Darkecha" is Your big path; "u'Shvilcha" is Your individual (small) path. Via what happened at the sea, all know that all is from You - the Klal and the Prat.
Why is it written u'Shvilecha, and we pronounce it u'Shvilcha?
Radak: The Kesiv (plural) teaches that there were many paths - "l'Gozer Yam Suf li'Gzarim" (136:13). The Mechilta (Shemos 14:16) says that there were 12 paths (one for each Shevet).
Why does it say "v'Ikevosecha Lo Noda'u"?
Rashi: The steps are not recognized on the water.
Radak: Your paths on the sea were not recognized, for the water returned on the Egyptians - "va'Yashav ha'Yam Lifnos Boker l'Eisano", "va'Yashuvu ha'Mayim va'Ychasu Es ha'Rechev v'Es ha'Parashim" (Shemos 14:27-28).
Malbim: Even though Your steps are not seen, all is the act of the One who formed Ma'ase Bereishis. The Mechilta says that when Moshe was praying, Hashem showed to him a group of angels standing in front of them.
