Answer to Eunomius' Second Book
He shows, I think, by the relation of these elements to each other, or rather by their distance, how far the divine nature is above the speculations of human reason. For that nature which transcends all intelligence is as high above earthly calculation as the stars are above the touch of our fingers; or rather, many times more than that.
Knowing, then, how widely the Divine nature differs from our own, let us quietly remain within our proper limits. For it is both safer and more reverent to believe the majesty of God to be greater than we can understand, than, after circumscribing His glory by our misconceptions, to suppose there is nothing beyond our conception of it.
Source: Answer to Eunomius' Second Book (New Advent)