Amos 3:10

For they know not to do right, saith the LORD, who store up violence and robbery in their palaces.

For they know not to do right - their moral corruption blinds their power of discernment, so that they cannot do right (, "My people is foolish, they have not known me; they are sottish children, and they have none understanding; they are wise to do evil, but to do good they have no knowledge"). Not simple intellectual ignorance: the defect lay in the heart and will.

Who store up violence and robbery in their palaces - i:e., treasures obtained by "violence and robbery" ().