What are the connotations of "es ha'Nochri Tigos"?
Ramban (citing the Sifri): It is a Mitzvas Asei 3 (not to claim one's debts from a Nochri, but) not to claim one's debt from a Yisrael after the Sh'mitah.
See Torah Temimah, note 14. Refer also to 15:3:151:2.
The fact that Rashi does not elaborate ? as he does in Ki Seitzei, 23:2 in connection with Ribis ? suggests that he explains the Pasuk literally (not like the Rambam.
Ramban: Because a La'av that one extrapolatess from an Asei is an Asei ? in addition to the Lo Sa'aseh "Lo Yigos" in the previous Pasuk. Refer also to 15:3:151:1 & 2 and notes.
Bearing in mind that stealing from a Nochri is forbidden (See Bava Kama, 113b), why is it permitted to claim one's debt from a Nochri after the Sh'mitah?
Ramban: Refer to 23:21:2:1 and note 2.
The Torah is informing us here that the debt of a Nochri is not negated by the Sh'mitah, in which case the question of stealing from the Nochri is not applicable.
What are the implications of "va'Asher Yih'yeh l'cha es Achicha Tashmeit Yadecha"?
Rashi (in the initial manuscript): It comes to preclude from the Mitzvah of Hashmatas Kesafim where the creditor already has a Mashkon (a security) against the loan from the debtor (because it is considered "Shel Achicha be'Yadecha" - Sifri). 1
Sifri: ?Tashmeit Yadecha" implies that if one hands over one?s Sh?tar Halva?ah to Beis-Din, the loan is not subject to Hashmatas Kesafim ? which explains why Hillel instituted a P?ruzbul 2 when he saw that creitors were unwilling to lend money beause they felt thar they may lose their money when the Sh?mitah cancelled their debts.
Rashi (citing the Sifri) says that "es ha'Nochri Tigos" is a Mitzvas Asei. What is the Mitzvah?
Ramban: It is an Isur Asei to claim a debt [after Sh'mitah] from a Yisrael. 1 It is not a Mitzvah to claim one's debt from a Nochri after the Sh'mitah. This is like "la'Nochri Sashich" (23:11). The Sifri calls also this an Asei, and Rashi explains there that it is an Isur Asei to take Ribis from a Yisrael.
Rambam (Hilchos Malveh 1:2): It is a Mitzvah to claim one's debt from a Nochri and cause him pain. 2
Ramban: Since a La'av that stems from an Asei is an Asei. The previous Pasuk said "Lo Yigos", and the Torah now comes to add a Mitzvas Asei.
The Ramban (Hilchos Malveh 5:1) similarly said that that it is an Isur Asei to take Ribis from a Nochri. The Ra'avad disagreed there, but not here. Perhaps it is because the end of our Pasuk explicitly teaches an Asei "Es Achicha Tashmet", so we do not infer another Asei from the beginning of the verse. (PF).