Likutei Sichos vol. 11 page 01 ff.
In the beginning and in the end, the difference. When the Yidden left Mitzrayim they were like sons of a father, where all are redeemed (even sinners), unless they refuse to be. When Moshiach comes, we will be chosen. Choice is only about the chooser, and not the chosen at all, consequently, no one is...
Likutei Sichos vol. 11 page 08 ff.
Moshe proposes that Moshiach redeem the Jews from Egypt rather than him, but Hashem tells him that now is his time, and Moshiach will use the Torah Moshe received to correct the world altogether.
Likuti Sichos vol. 11 page 24 ff. (1).
The first three plagues punished the Egyptian gods, only from the fourth plague and on were the Egyptians themselves being punished. Therefore only from the fourth plague on was the difference between the Jews and the Egyptians very noticeable.
Likutei Sichos vol. 11 page 24 ff. (2).
Continued. The Midrash sees all the מכות beginning with the very first as a series of steps to exhaust Egypt, accordingly ערוב wasn’t about killing Egypt but to confuse them, thus the name: ערוב.