Adam Clarke on Job 38:3

Gird up now thy loins - I will not confound thee with my terrors; dismiss all fearful apprehensions from thy mind; now act like a man, כגבר kegeber, like a hero: stand and vindicate thyself. For I will demand of thee - I will ask thee a series of questions more easy of solution than those which thou hast affected to discuss already; and then thou shalt have the opportunity of answering for thyself. The most impressive and convincing manner of arguing is allowed to be that by interrogation, which the Almighty here adopts. The best orations delivered by the ancients were formed after this manner. That celebrated oration of Cicero against Catiline, which is allowed to be his masterpiece, begins with a multitude of short questions, closely pressed upon each other. See the end of the chapter, Job 38:40 (note).