He paweth; or, he diggeth. Through courage and wantonness he cannot stand still, but is beating, as it were digging, up the earth with his feet. In the valley: this he adds, partly because the ground being there more plain and smooth, he hath the better conveniency for his prancing and pawing with his feet, which in hilly and uneven ground he cannot so well do; and partly because battles use to be pitched in valleys, or low grounds, especially horse battles. Rejoiceth in his strength; making semblance of great pride and complacency in it. He goeth on to meet the armed men, with great readiness and undaunted courage.
Related Commentaries of Job 39:21
Job 39:21
21 He pawethd in the valley, and rejoiceth in his strength: he goeth on to meet the armed men.