The simple reading of this text tells us that when someone decides to lend, he should not be overly demanding during collection or charge interest. According to Chazal (Mechilta, cited by Rashi), there is a positive mitzvah to lend money. It is stated that one must lend, making lending a mitzvah.
The Chafetz Chaim emphasizes that lending is a greater mitzvah than Tzedakah. Sefer Hachinuch explains that lending maintains the dignity of the borrower, as opposed to accepting charity.
There is also a negative commandment related to lending, as mentioned in Parshat Re’eh. The Torah instructs us not to be stingy when lending, even when fearing the borrower may not repay the loan after a certain period. This highlights the importance of generosity in lending.
While it may seem like lending is optional due to the use of the term “אם” (if), there are various circumstances that can impact one’s ability to fulfill this mitzvah. Maharal explains that lending should be done with a generous heart, not as a mere obligation.
Shabbat Shalom.