What is the La'av of "Lo Sasgir Eved el Adonav" referring to?
Rashi #1 (citing Targum Onkelos), Ramban #1 and Targum Yonasan: It refers to (Beis-Din-in Kidushin, 63a) handing back the slave of a Nochri who runs away from his master 1 (in the enemy camp during wartime - Ramban) 2 and comes to you for asylum (even if he offers you money - Ramban). 3
Rashi #2 and Ramban #2 (citing Gitin, 45a): It refers even to an Eved Cana'ani who runs away from his Jewish master in Chutz la'Aretz and comes to you for asylum in Eretz Yisrael. 4
As opposed to one who runs away from his Jewish master, whom one is obligated to return. See Oznayim la'Torah.
See Torah Temimah, note 80.
Ramban: Provided he undertakes to discontinue worshipping idols. See also Sifsei Chachamim and refer to 23:17:1:1.
Irrespective of who the master is, Rashi in Kidushin, 63a states that the La'av pertains to the Beis-Din not to hand the Eved back to his master. See also Oznayim la'Torah DH 'Lo Sasgir Eved el Adonav' and DH 'Eved el Adonav' who elaborates.
Why is it forbidden to return the slave to his master?
Ramban #1 and Targum Yonasan: Because he wants to give up idolatry and came to us in order to serve Hashem. 1 Consequently, it is not correct to send him back to his master to worship idols.
Ramban #2: Because by taking him under our wing, it is possible that he will divulge secrets 2 regarding the enemy that will enable us to defeat them. 3
Ramban: As we find that many a country was captured thanks to the information provided by slaves who fled from their masters or by captives (See for example, Shmuel 1, 30:13 ? 17 - EC).
See R. Chavel's notes.
What is the connection between the previous Parshah and the two current Parshiyos?