Commentary for Job 23:13

But He Since He is One in the world and knows the knowledge and the thoughts of the creatures, and what they have to reply to Him, therefore replies are prepared before Him.

Job maintains that everything that has happened to him was preordained by reason of God’s foreknowledge. And since His Knowledge is immutable, whatever He foreknows must happen; there is no free-will. For the existence of free-will would require that God’s Knowledge change as man makes his choices or changes his mind. But that cannot be, for He is His Knowledge and He is beyond change.

and who will answer Him Therefore, what His soul desires, He does.