וַיּ֨וֹשַׁע יְהוָ֜ה בַּיּ֥וֹם הַה֛וּא אֶת־יִשְׂרָאֵ֖ל מִיַּ֣ד מִצְרָ֑יִם וַיַּ֤רְא יִשְׂרָאֵל֙ אֶת־מִצְרַ֔יִם מֵ֖ת עַל־שְׂפַ֥ת הַיָּֽם׃
I ocalił Wiekuisty dnia onego Israelitów z rąk Micrejczyków; i widział Israel Micrejczyków martwych na brzegu morza.
Rashi
וירא ישראל את מצרים מת AND ISRAEL SAW THE EGYPTIANS DEAD — because the sea threw them out on its shore in order that the Israelites should not say: “Just as we have come up from out of the sea on this part, so they have come up on another part of this shore, but far away from us, and they will pursue us” (Mekhilta; Pesachim 118b; Arakhin 15a).
Alshekh
The people feared. This refers to the mixed multitude who had not beheld a clear vision of Hashem. Therefore it was only through the deaths of the Egyptians that they acquired awe and faith. For B’nei Yisrael themselves, by contrast, this was unnecessary.
Chizkuni
ויושע ה' ביום ההוא, “on that day the Lord delivered;” this verse testifies to G-d’s having kept His promise of “'התיצבו וראו את ישועת ה, “stand firm and watch the deliverance orchestrated by Hashem!” This day was one of complete deliverance, as from that day on the Israelites did not see any more Egyptians in their lives [that generation. Ed.]) את מצרים מת, the Torah refers to all of them in the singular mode. We find other examples of this construction in the Holy Scriptures, the most recent one being in verse 10 of our chapter: והנה מצרים נוסע אחריהם, “and here Egypt was travelling behind them.”