Surely I am more brutish than [any] man,.... "Every man is [become] brutish in his knowledge"; man in his original state was a knowing creature but sinning lost his knowledge, and "became like the beasts that perish"; hence we read of the "brutish among the people": but Agur thought himself not only brutish among the rest, but more brutish than any.
So Plato says of some souls living on earth, that they are yhriwdeiv, of a brutish nature; see Jer 10:14.