It states in Exodus 22:24: ‘If (im) you lend money to My people, to the poor among you, do not act toward them as a creditor; exact no interest from them.’ In Mechilta d’Rabbi Yishmael (Mishpatim, ch. 19), it clarifies that the interpretation of this verse is that it is not optional, but there is an obligation to lend money to the poor:
R. Yishmael said: wherever ‘im’ occurs in Scripture it is used of an act the performance of which is optional, except in three instances, of which this is one. Other cases include Exodus 20:22: ‘And if (when) you make for Me an altar of stones, do not build it of hewn stones,’ and Leviticus 2:14: ‘And if (when) thou offerest the meal-offering of… Read More »