What does the Torah mean when it writes that Yisrael went out "be'Yad Ramah"?
Rashi and Targum Yonasan: It means that Yisrael left Egypt in triumph (over the downfall of the Egyptians).
Ramban: Refer to 14:5:2:2.
Rashbam: They left totally free, unworried about being recaptured - until they saw the Egyptians at the Yam-Suf.
Seforno: They left Egypt with the misconception that, since they outnumbered the Egyptian army, they would be able to defeat them. 1
Until they saw them in battle array, with all their chariots. The Torah is demonstrating their total lack of understanding of matters concerning warfare (Seforno).