"The Lord Yahweh has sworn by himself," says Yahweh, the God of hosts: "I abhor the pride of Jacob, And detest his fortresses. Therefore I will deliver up the city with all that is in it.
"I abhor the excellency of Jacob ..." This expression shows that Amos never has Judah very far out of mind; for Jacob was the ancestor of Judah, as well as of Israel.  Writers who try to make out that these various references to Judah, Jacob, and the whole house of Israel which came up out of Egypt, etc. are added to the prophecy by later writers are totally wrong.  Despite the principal burden of Amos' commission having been to cry out against the Northern Kingdom, unless he had kept before them continually the reminder that God was also displeased with similar sins in Judah, he would have lost his effectiveness through the appearance that he was merely crying out against the sins of his neighbor, and not against the sins of his own nation.