On its surface, Parashat Ki Teitzei appears to simply be a list of Mitzvot, ostensibly just Moshe’s way of recording all of the commandments that needed to be said. The contents of the Parashah range from the Halachot pertaining to Ben Soreir UMoreh (the wayward son) to laws regarding Hashavat Aveidah (returning lost objects), vastly different Mitzvot. But even though the Mitzvot in Ki Teitzei appear to be entirely unrelated, in reality, there is a powerful underlying theme that unites these commandments. The Mitzvot, while seemingly small and unrelated, are actually potent catalysts for increased unity among the Jewish people. The Mitzvot of Parashat Ki Teitzei require the Jews to act more kindly to one another and hold themselves to a higher standard than any of the other surrounding nations. A prime example of such a Mitzvah is Lo Tashich, the prohibition of charging interest to other Jews.
The prohibition of charging interest first appears in Sefer Vayikra (25: 36-37). The Pasuk writes “Al Tikach Mei’Ito Neshech VeTarbit VeYareita Mei’Elokecha VeChai Achicha Imach,” “Do not take from him advanced or accrued interest, but fear your God and let your brother live among you.” The Seforno (s.v. Al Tikach Me’Ito) writes that refraining from charging interest is the ethically proper way of supporting a fellow Jew who is experiencing financial difficulty. For the first time, we see that charging interest in not an inherently criminal act; it is a perfectly acceptable method of conducting business amongst the other nations. The Torah seemingly prohibited this business practice, however, to foster unity among the Jewish people. By going above and beyond the standard practices that other nations utilize, a much greater sense of unity is created. This point is further solidified by the conclusion of the Pasuk. After prohibiting the charging of interest, the Torah writes that you must let your brother live among you (if they are in great financial trouble). This juxtaposition suggests that both components of the Pasuk have similar messages. Refraining from charging interest accomplishes the same goal as providing your brother with a home, it is an act of brotherly kindness that fosters greater unity.
There are two other sources for the prohibition of charging interest: Shemot (23:24) and Devarim (23: 20-21). In Shemot, the Pasuk records “Im Kesef Talveh Et Ami Et Ha’Ani Imach Lo Tihiyeh Lo KeNosheh Lo Tesimun Alav Neshech, “If you lend money to my nation, to the poor among you, do not be a creditor for them, do not take interest from them.” The Pesukim in our Parashah, Ki Teitzei, share some similarities, but also have numerous differences: “Lo Tashich LeAchicha Neshech Kesef Neshech Ochel Neshech Kol Davar Asher Yishach: LaNochri Tashich ULe’Achicha Lo Tashich...” “You shall not charge your brother interest, whether it be money, food, or anything that can be charged as interest: You may charge interest to foreigners, but not your brothers…” Rav Yoel Bin Nun wrote in article entitled “Practical Mitzvot” that these sources emphasize the fraternal context of the Mitzvot. The Torah repeatedly states that you may not charge interest to your brother or the poor among you, but it is permitted where non Jews are concerned. He stated that “This indicates that interest is not an absolute moral prohibition, like theft, but rather a special kindness or consideration shown to Jews, by virtue of the Exodus.”
A similar theme is developed by the Ibn Ezra in his commentary to the Pesukim in Ki Teitzei. He explains (Devarim 23:20 s.v. Lo Tashich LeAchicha) why the Pasuk needed to include the words “LaNochri Tashich,” “You may charge a foreigner interest.” Since the Torah had stated just three Pesukim earlier that you may not oppress a non-Jewish slave, you may have assumed that charging interest is included in that category. Therefore, by specifying that you are still permitted to charge a non-Jew interest, it shows that it is not an inherently problematic action. It is not considered oppression that the Pasuk would have otherwise forbidden. Similarly, the Ramban (ibid s.v. Lo Tashich Le’Achicha) writes that the prohibition against charging interest is different from all other Mitzvot that involve money, because it applies both to the lender and the borrower. Not only is the lender prohibited to charge interest, but a borrower cannot accept a loan that includes interest. The Ramban explains that this double prohibition was created to ensure that a sense of brotherhood and kindness is perpetuated among the Jewish people. It is not prohibited because it is an inherently criminal action, like stealing, but rather as an extension of “VeAhavta LeRei’acha Kamocha.” This idea is the true message of the seemingly piecemeal nature of Parashat Ki Teitzei. Simply treating a Jew in a neutral manner, neither positive nor negative, is not acceptable. You must go above and beyond, and do whatever you can to help a fellow Jew through acts of kindness.