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 7

7:8 And the LORD said unto me, Amos, what seest thou? And I said, A plumbline. Then said the Lord, Behold, I will set a plumbline in the midst of my people Israel: I will not again pass by them any more: