John Gills Exposition of the Bible Commentary - Job 39:21
He paweth in the valley ,.... Where armies are usually pitched and set in battle army, and especially the cavalry, for which the valley is most convenient; and here the horse is impatient of engaging, cannot stand still, but rises up with his fore feet and paws and prances, and, as the word signifies, digs the earth and makes it hollow, by a continual striking upon it; so generally horses are commonly described in this manner F19 "Cavatque tellurem". Virgil. Georgic. l. 3. v. 87. ; ... read more
Matthew Henry's Complete Commentary - Job 39:19-25
God, having displayed his own power in those creatures that are strong and despise man, here shows it in one scarcely inferior to any of them in strength, and yet very tame and serviceable to man, and that is the horse, especially the horse that is prepared against the day of battle and is serviceable to man at a time when he has more than ordinary occasion for his service. It seems, there was, in Job's country, a noble generous breed of horses. Job, it is probable, kept many, though they are... read more