אֶ֨ת־כַּסְפְּךָ֔ לֹֽא־תִתֵּ֥ן ל֖וֹ בְּנֶ֑שֶׁךְ וּבְמַרְבִּ֖ית לֹא־תִתֵּ֥ן אָכְלֶֽךָ׃
Thou shalt not give him thy money upon interest, nor give him thy victuals for increase.
Read kabbalistic (mystical) interpretation of Leviticus 25:37: and classical mystical sources.