1)
What is "Raga ha'Yam"?
1.
Rashi: It is folded, like "Ori Raga." When Hashem told the water to gather, it ceased to be smooth, and was greatly folded, until it entered the place prepared for it.
2.
Ibn Ezra: He split the sea.
3.
Malbim: The rain cycle calms the sea, that it will not return to cover the land.
2)
What is "Rahav"?
1.
Bava Basra 74b: It is the Sar of the sea. When Hashem wanted to create the world, he told it to open its mouth and swallow all the water. It did not want to;
Hashem struck it and killed it. Malbim - the Nimshal is, initially oxygen was mixed with the water, and it covered the entire land. Hashem removed the oxygen, and then the ocean could contain the water.
1
Rashi: The Egyptians.
