What is the La'av of "Lo Sasgir Eved el Adonav" referring to?
Rashi #1 (citing Targum Onkelos) and Ramban: It refers to handing back the slave of a Nochri who runs away from his master and comes to you for asylum 1 (even if his master offers you money - Ramban).
Rashi #2 (citing Gitin, 45a): It refers even to the Eved Cana'ani who runs away from his Jewish master in Chutz la'Aretz and comes to you for asylum in Eretz Yisrael.
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.
What is the connection between the previous Parshah and the two current Parshiyos?