Work was strictly forbidden on the Sabbath day (Exodus 20:9–10). Amos suggests that shops also closed during pagan new-moon religious festivals.
Merchants cheated their customers by using small ephahs (containers for measuring grain), so buyers received less than they paid for. They also cheated their suppliers by using heavy shekels (weights of silver) on their scales, so sellers received less payment. God’s law clearly forbade these dishonest practices (Leviticus 19:35–36; Deuteronomy 25:13–16; see Proverbs 11:1; 16:11; 20:10, 23).