Moshe seems to have given a variety of answers to a variety of groups. How many groups were there and how did he answer each one?
Targum Yonasan: There were four groups at the Yam-Suf: One said that they should proceed into the sea, and one, that they should return to Egypt; 1 one wanted to fight the Egyptian and one, to frighten them (by clashing their swords and shields and stomping their horses). To the first group Moshe said "Do not be afraid; stay where you are and see the salvation of Hashem"; to the second group he said "Do not go back, because as you see the Egyptians today you will never see them again"; To the third group he said "Do not attack them, because your victory will come about through Hashem"; and to the fourth group he told to be silent and to sing the praise of Hashem and to honor and elevate Him.
What are the ramifications of the last phrase in the Pasuk?
Rashi #1, Targum Onkelos and Targum Yonasan: Do not return to Egypt, because they are all about to die. 1
Rashi #2 (Sanhedrin, 21b) and Ramban (citing the Mechilta): This is actually a Mitzvah never to return to Egypt. 2