John Gill

A horse is a vain thing for safety,.... Though it is prepared for the day of battle, and is a very warlike creature, and of great service in war, yet safety only is of the Lord, Pro 21:31; this is put for all kinds of military preparations which men are apt to trust in, but should not, for they are "a lie" (i), as the horse is here said to be; that is, deceives and disappoints when trusted to; in like manner the olive is said "to lie", Hab 3:17; when hope of fruit from it is disappointed; so "fundus mendax" in Horace (k); neither shall he deliver any by his great strength; in the time of battle; either by fighting for him, or fleeing with him. (i) "mendacium", Pagninus, Montanus; "fallax", V. L. (k) Epod. l. 1. Ode 16. ver. 45. Carmin. l. 3. Ode 1. v. 30. "Spem mentita seges", ib. Epist. l. 1. ep. 7. v. 87.