For whoever acknowledges the mitzvah of interest: [this] shows that he believes in Hashem, that He watches over the world and provides for them and sustains them, and that he will not lack from His bounty so much as a hair’s breadth, even if he does not take interest. And this [Hashem] showed us in the land of Egypt, that He is the G-d of the world, as it is written, “So that you will know that I am Hashem in the midst of the land” (Shemos 8:18). And whoever denies the mitzvah of interest, who thinks in his heart that his livelihood depends only on his strength and the might of his hand, and that this will make him wealth (Devarim 8:17), shows that he denies [Hashem’s] providence.