# who by a word make a man out to be an offender

"who testify against a man and make him out to be an offender" or "who say in court that an innocent man is guilty of doing something wrong" 

# They lay a snare for him who seeks justice at the gate and put the righteous down with empty lies

"They lie and try to stop those who want to do what is fair and right" 

# who seeks justice at the gate

The city gate was often the place where the city leaders made official decisions.