Transgressions of Maob, Judah, Israel

Amos 2:1-16
For three transgressions of Maob, Judah, Israel and for four, I will not revoke the punishment, because of....
Reasons: 1)burned to lime the bones of the king of Edom. 2)they have rejected the law of the Lord, and have not kept his statues. 3)they sell the righteous for silver, and the needy for a pair of sandals.
He who is stout of heart among the mighty shall flee away naked in that day, declares the Lord.
By desecrating a corpse Moab has violated on of the most universal of all ancient unwritten laws. God will punish each and everyone. No doubt the listening Israelites were happy to hear their enemies condemned.
But Amos does not stop there. Judah too is condemned. Now the prophet is getting uncomfortably close to home.
Even so, nothing can have prepared his hearts for the shocking punch-line, the refrain that this time is for them: 'For crime after crime of Israel I shall grant them no reprieve'. This was the main purpose of Amos' preaching: to warn the Israelites that they too were under the judgments of God.
Why?
Hosea makes it plain that Israel's basic sin was in turning away from God to worship idols. But Amos emphasizes the moral and social decline which resulted. They have grown hard and callous in their dealings with others.
By famine and drought, blight and disease God had warned them where they were heading - all to no avail.
How?
Listen to the warning of God's word and the sign from the Lord!