Albert Barnes Commentary Amos 8:6

"that we may buy the poor for silver, and the needy for a pair of shoes, and sell the refuse of the wheat?" — Amos 8:6 (ASV)

That we may buy - Or, indignantly, “To buy the poor!” literally, “the afflicted,” those in “low” estate. First, by dishonesty and oppression they gained their lands and goods. Then the poor were obliged to sell themselves. The slight price, for which a man was sold, showed the more contempt for “the image of God.” Before, he said, the needy were sold for a pair of sandals (Amos 2:6); here, that they were bought for them. It seems then the more likely that such was a real price for man.

And sell the refuse - Literally, the “falling of wheat,” that is, what fell through the sieve: either the bran, or the thin, unfilled grains which had no meal in them. This they mixed up largely with the meal, making a gain from that which they had once sifted out as worthless; or else, in a time of dearth, they sold to people what was the food of animals and made a profit on it. What an infancy and inexperience of cupidity, which adulterated its bread only with bran, or sold to the poor only what, although unnourishing, was wholesome! But then, with the multiplied hard-dealing, how manifold the woe!