Why does the Torah insert "Ki Li Bnei Yisrael Avadim"?
Rashi: To explain that Hashem's document of sale (purchasing Yisrael as Avadim) preceded the Nochri's. 1
Ramban (47), Moshav Zekenim (47): Even though the Nochri is not subject to the laws of Yovel, they do not have the authority to buy Hashem's servants as [permanent] slaves.
Targum Yonasan: Yisrael are Hashem's Avadim in that they are subservient to His Torah, and may not be enslaved by others. 2
Moshav Zekenim citing Bava Metzi'a 10a: A worker can quit in the middle of the day (for he is not the employer's slave)
Why does the Torah insert "Ani Hashem Elokeichem"?
Rashi: To teach us that whoever enslaves them on earth, it is as if he has enslaved them above. 1
Da'as Zekenim: I (Hashem) explain why I will redeem Yisrael even if they lack Mitzvos, It says also here "Lo Sa'asu Lachem Elilim" - at least they fulfilled "Lo Yihyeh Lecha Elokim Acherim"
Maskil l'David: With reference to the root of their Neshamos.
We learn from "Ki Li Bnei Yisrael Avadim" that a worker can quit in the middle of the day (Bava Metzi'a 10a). Why do we need "v'Hefdah" to teach that one may redeem an Amah Ivriyah?
Moshav Zekenim citing Ri: There, the Torah fixed six year of servitude. One might have thought that she cannot leave until they finish.
Why does the verse begin in the third person ("Ki Li Bnei Yisrael
Moshav Zekenim: Most verses that discuss Yetzi'as Egypt are like this, because there were some in Goshen,and some in Tzo'an, the capital with Bnei Efrayim and Menasheh. 1 Sometimes it discusses Yisrael, and sometimes the Erev Rav. "Ki Li Bnei Yisrael Avadim" discusses those in all Mitzrayimm) and "Ani Hashem Elokeichem" discusses those with Pharaoh in Tzo'an.
He assume that Yosef's descendants remained in the capital. I do not know his source. (PF)