What did Isaiah mean by calling on Judah to seek justice and correct oppression?

For the prophet Isaiah, calling on Judah to "seek justice" and "correct oppression" was a fundamental moral demand rooted in the Covenant between God and his people. Isaiah believed that this relationship was conditional, contingent upon the ethical conduct of the nation.1

By these commands, Isaiah meant that the people—particularly the leaders—needed to abandon their focus on superficial religious rituals, which he viewed as irrelevant or even repugnant when accompanied by social injustice. Instead, he urged them to prioritize moral behavior, specifically by defending the fatherless and pleading for the widow.12

Isaiah’s message was a direct response to the rampant inequities of 8th-century BCE society, where the wealthy exploited the poor, judges accepted bribes, and the innocent were deprived of their rights. He held the conviction that true security for the nation could not be found in military might or political alliances, but only in a "reconciling response to the moral demand"—essentially, that no one is secure when others are denied justice. Ultimately, he sought to redirect his people toward ways of life acceptable to God to save them from impending catastrophe.234