Amos is the book of the herdsman from Tekoa, a small town in Judah. He receives a direct call from God to prophesy against the unrighteousness of both Judah and Israel. Amos is the first prophet to proclaim that God is the ruler of the whole world.

Amos 6

6:12 Shall horses run upon the rock? will one plow there with oxen? for ye have turned judgment into gall, and the fruit of righteousness into hemlock: