Based on the wording describing the splitting of the Red Sea, the sages learn that all the waters on the earth split, not just the Red Sea. The Torah, teshuvah (return to God), and the Almighty Himself are likened to war, suggesting that they too experienced a type of split. Harav Ginsburgh explains the meaning of the split in the spiritual realm.
Beshalach: Splitting of the Waters Above and Below
