Albert Barnes Commentary Amos 3:10

"For they know not to do right, saith Jehovah, who store up violence and robbery in their palaces." — Amos 3:10 (ASV)

For - (and) they do not know how to do right. They have not known; they have lost all sense and knowledge of how to do right (literally, what is straight-forward), because they had so long ceased to do it. It is part of the miserable blindness of sin that while the soul acquires a quick insight into evil, it becomes, at last, not only paralyzed to do good, but unable to perceive it. So Jeremiah says, they are wise to do evil, but to do good they have no knowledge (Jeremiah 4:22). This is why Paul says of the Christian, I would have you wise unto that which is good, and simple concerning evil (Romans 16:19).

People, step by step, lose the power of understanding either good or evil, the love of the world or the love of God. Either becomes a strange language to ears accustomed to the songs of Zion or the din of the world. When our Lord and God came to His own, they said, we know that God spake unto Moses: as for this man we know not whence He is (John 9:29). And this blindness was brought about by covetousness, which blindeth the eyes even of the wise (Exodus 23:8), as he adds:

Who store - (Literally, with indignation, the storers)

With violence and robbery - They could not understand what was right, while they habitually did what was wrong. They stored up, as they deemed, the gains and fruits; the robbery and injustice they did not see, because they turned away from seeing.

But what is stored up is not what wastes away, but what abides. Who doubts it? Then, what they treasured were not the perishing things of earth but, in truth, the sins themselves, as a treasure of wrath against the Day of wrath and revelation of the righteous judgment of God (Romans 2:5).

Strange treasure, to be so diligently accumulated, guarded, and multiplied! Yet it is, in fact, all that remains. So is he that layeth up treasure for himself and is not rich toward God (Luke 12:21).

He adds, as an aggravation, in their palaces. Deformed as in all oppression, yet to oppress the poor, to increase his riches (Proverbs 22:16) has an unnatural hideousness of its own. What was wrung from the poor, laid up in palaces! Yet what else is it to cheapen luxuries at the cost of the wages of the poor?