Thomas Aquinas

Second, they put great faith in a small and frail thing, and so he says, "he," the adulterer, "is light on the surface of the waters," as if to say: He moves so lightly that it seems to him that he can pursue his own will as though he were sailing on calm seas. Or one can also explain the literal sense, "they walk in darkness as in light," in that both the adulterer and the adulteress love to do their works in the dark. …

Commentary on Job ↗