Amos 4 begins with a sharp name: Listen to this word, you cows of Bashan, who are on the mountain of Samaria, who oppress the poor, who crush the needy, who tell their husbands, Bring us drinks! Bashan's cattle grazed on rich land. The rich women of Samaria lived in comfort built on the suffering of the poor. The Lord Yahweh has sworn by his holiness that a day of judgment would come.
Amos then imitates a call to worship, but twists it: Go to Bethel, and sin; to Gilgal, and sin more. Bring your sacrifices every morning, your tithes every three days. They proclaim free will offerings and brag about them; for this pleases you, you children of Israel. Their religion pleased themselves, not God.
God had sent warning after warning. I also have given you cleanness of teeth in all your cities, and lack of bread in every town; yet you haven't returned to me. He withheld the rain, sent blight and mildew, and the swarming locusts. God said, I have overthrown some of you, as when God overthrew Sodom and Gomorrah, and you were like a burning stick plucked out of the fire; yet you haven't returned to me. So the chapter ends: prepare to meet your God, Israel. He who forms the mountains, creates the wind, declares to man what is his thought. Yahweh, the God of Armies, is his name.