Why does the Torah write "Es Kasp'cha" and "Ochlecha" and not 'Kesef' and 'Ochel' S'tam?
Sifra: To preclude the money and the food of a Nochri, which one is permitted to lend on interest. 1
See Torah Temimah, note 196.
Why does the Torah insert the word "Lo Sitem Lo"?
Bava Metzi'a, 69b: To restrict the Isur Ribis to Ribis that goes directly from the Loveh to the Malveh, but not to where Reuven gives Shimon a Zuz in order thatt he lend Levi ten Dinrim or in order to ask Levi to lend him ten Dinrim. 1
See Torah Temimah, note 199, who elaborates.
What is the difference between this Pasuk and the Pasuk in Ki Seitzei, Devarim 23:20 "Lo Sashich la'Achicha Neshech Kesef ..."?
Rashi (in Devarim 23:20): The current Pasuk places a La'av on the person who lends on interest, whereas the Pasuk there places a La'av on the Loveh. 1
Bava Metzi'a, 61: The Pasuk there also teaches us Neshech by food and Ribis by Kesef. 2
Why does the Torah write "Marbis" here and "Tarbis" in the previous Pasuk?