Sforno on Exodus 15:15/ספורנו על שמות ט״ו:ט״ו

1אז נבהלו אלופי אדום, אילי מואב, when they saw all these miracles; even though they knew that Israel would not make war against them. They were still frightened by the mere spectacle even if it was not directed at them.

2יאחזמו רעד, they were gripped by fear praying that the Israelites would never rise to attack them.

3נמוגו כל יושבי כנען, there can be no question that the hearts of all the inhabitants of the land of Canaan melted at the manifestation of these miracles as they knew that the Israelites were marching in order to drive them out of their land. Rachav testifies even 40 years later when their worst fears had not yet been realised, that the population of Canaan had completely lost confidence in the outcome of a confrontation with Israel (Joshua 2,11).