The accusation is made in Amos 2:6. The Mosaic law allowed for debt slavery (Exodus 21:2–11; Deuteronomy 15:12–18). If someone had a large debt to repay or was unable to feed himself or provide for his family, he could sell himself into slavery. This social net would provide him with food and prevent starvation. It seems as if in Israel, people were being sold into debt slavery for trivial amounts (e.g. the price of a pair of sandals). This was contrary to the loving purpose of the law. Most likely corrupt courts helped the rich by facilitating this and making cheap labour available to them.1
6 that we may buy the poor for silver and the needy for a pair of sandals and sell the chaff of the wheat?”