Behar: Kli Yakar: Bitachon to not Collect Interest
The 7th of Iyar is the Yahrtzeit of Rav Shlomo Ephraim of Luntchitz, author of Kli Yakar: “If your brother becomes impoverished and his means falter in your proximity, you shall strengthen him, proselyte or resident, so that he can live with you. Do not take from human interest and increase; and you shall fear your Lord, and allow your brother to live with you (Vayikra 25:35-36).”
The main idea behind the probation of collecting interest is that one who insists on interest removes from himself the attribute of trust in God, not only from himself, but from others as well. For all people who are involved in business lift their eyes to God so that He will provide. One who collects interest and one who pays interest is simply relying on the workings of money and is removing God’s control from his heart.