Job 9:3

if he will contend Or, if he would; if he (man) should desire to contend with God. "To contend" is a legal term meaning to enter a plea with, the idea of a court or judge being in the mind of the speaker. Here man is supposed to have a plea with God on the question of his innocency, or on any question involving his righteousness. The question in Job 9:4, "Who hath hardened himself against Him?" makes it probable that man is here considered the appellant. Others take the subject to be God: if He were pleased to contend with him(man), cf. Job 9:14; Job 9:16. This suits the second half of the verse, but seems less suitable to the general connexion.

he cannot answer him Or, he(man) could notanswer him (God) one of a thousand of the questions with which in His infinite wisdom (Job 9:4) He would ply him.