They sold the righteous for silver. The first charge against Israel is perversion of justice. The judges took bribes and condemned the righteous, i.e. the man whose cause was good. Pusey thinks that the literal selling of debtors by creditors, contrary to the Law (Exodus 21:7; Le Exodus 25:39; Nehemiah 5:5), is meant (comp.
Amos 8:6 and Matthew 18:25). The needy for a pair of shoes. For the very smallest bribe they betray the cause of the poor (comp. Ezekiel 13:19); though, as sandals were sometimes of very costly materials (So Amos 7:1; Ezekiel 16:10; Judith 16:9), the expression might mean that they sold justice to obtain an article of luxury.
But the form of expression is opposed to this interpretation.