Amos 5:12
For I know your manifold transgressions and your mighty sins: they afflict the just, they take a bribe, and they turn aside the poor in the gate from their right. For I know your manifold transgressions and your mighty sins: they afflict the just, they take a bribe, and they turn aside the poor in the gate from their right.
The gate is the place where legal matters were heard. The verse exposes three specific injustices committed there: afflicting the just, taking bribes, and turning the poor aside from their rightful justice in court. In Israel those injustices followed departure from true worship and a turn to idolatry. They were part of the oppression and corruption denounced by the prophets.
The prophets protested these evils and called the people to abandon them through right-doing. Their protests over these sins were rejected. The verse also describes the world's condition just before the Lord's second coming, identifying widespread transgression and injustice as features of that time.