Job 39:18 - Ellicott's Commentary On The Whole Bible

She lifteth up herself. — That is, either from the nest when she comes to maturity, or when she sets out to run. The ostrich has a habit of running in a curve, which alone enables horsemen to overtake and kill or capture her. As in Job 39:13 a comparison seems to be drawn between the ostrich and the stork, so here, probably, the subject spoken of is the stork. Swift and powerful as the ostrich is, yet no sooner does the stork, on the contrary, rise on high into the air than she — as, indeed, any bird — can baffle the pursuit of horsemen.