You can’t charge interest on loans:
In this week’s parsha, Hashem gives over a set of 57 laws to the Jewish people. One of those laws in particular is the mitzvah of free loans. This mitzvah is based on the belief that Hashem and the Torah are in control of the wealth and the possessions we do or do not have. The law continues describing that any wealth one has, large or small, is entirely from Hashem, and rather, everything a person owns belongs to those who need it most urgently.
For example, if a neighbor of yours is going through financial distress with a failing business, and you have the wealth to help him; you must rush to his aid in assistance. Hashem has given people wealth and success in order for them to assist those in need.
Moreover, many people question why others possess more than they do; however, Hashem wants a rich man to support a poor man, and not out of mercy, but because Hashem deems it as a law. Additionally, Rashi commentates, “See yourself as a poor man.” In other words, by putting ourselves in a poor mans place, and picturing ourselves with nothing, we can recognize the importance of free loans.
Many people are blessed from Hashem with the ability to give charity to those in need. However, those people should not applaud themselves too much, which can result in arrogance, since Hashem is the One who bestowed that wealth upon them for the purpose of giving those in need. No matter how much we do amass throughout our lives, we should recognize that it is all a gift from Hashem, a gift we are lawfully required to share with those in need.