Jamieson, Fausset and Brown on Leviticus 25:35-38

35-38. if thy brother be waxen poor, ... relieve him--This was a most benevolent provision for the poor and unfortunate, designed to aid them or alleviate the evils of their condition. Whether a native Israelite or a mere sojourner, his richer neighbor was required to give him food, lodging, and a supply of money without usury. Usury was severely condemned (Psa 15:5; Eze 18:8, 17), but the prohibition cannot be considered as applicable to the modern practice of men in business, borrowing and lending at legal rates of interest.