1)
What is "mi'Yad Sonei"?
1.
Radak: It is from the Egyptians - "va'Yosha Hashem ba'Yom ha'Hu Es Yisrael mi'Yad Mitzrayim" (Shemos 14:30).
2)
Why does it add "va'Yig'alem mi'Yad Oyev"?
1.
Malbim: An Oyev's hatred is more revealed; he seeks the evil of the one whom he hates. He did not merely save temporarily - "va'Yig'alem", He permanently removed them from their Reshus (Eretz Mitzrayim).
