5 saying, “When will the New Moon be over that we may sell grain, and the Sabbath be ended that we may market wheat?”— skimping on the measure, boosting the price and cheating with dishonest scales,

Read Amos 8:5 Using Other Translations

Saying, When will the new moon be gone, that we may sell corn? and the sabbath, that we may set forth wheat, making the ephah small, and the shekel great, and falsifying the balances by deceit?
saying, "When will the new moon be over, that we may sell grain? And the Sabbath, that we may offer wheat for sale, that we may make the ephah small and the shekel great and deal deceitfully with false balances,
You can’t wait for the Sabbath day to be over and the religious festivals to end so you can get back to cheating the helpless. You measure out grain with dishonest measures and cheat the buyer with dishonest scales.