Question
How do we know that loans must be repaid?
Answer
Interestingly, the very important mitzvah of returning borrowed money is not explicit in the Torah; but it is quite clearly stated elsewhere in the Bible and in the Mishnah. “A wicked borrower who does not pay” is mentioned in Psalms 37:21, and the Mishnah (Avos 2:14) gives this as an example of an especially evil practice.