Rather, “Who make a man guilty in his cause” [Gesenius], that is, unjustly condemn him. “A man” is in the Hebrew a poor man, upon whom such unjust condemnations might be practiced with more impunity than on the rich; compare Isa 29:19, “the meek ... the poor.”
him that reproveth - rather, “pleadeth”; one who has a suit at issue.
gate - the place of concourse in a city, where courts of justice were held (Rth 4:11; Pro 31:23; Amo 5:10, Amo 5:12).
just - one who has a just cause; or, Jesus Christ, “the Just One” [Horsley].
for a thing of naught - rather, “through falsehood,” “by a decision that is null in justice” [Barnes]. Compare as to Christ, Pro 28:21; Mat 26:15; Act 3:13, Act 3:14; Act 8:33.