The point is, that I can imagine myself trying to describe exactly this sensation, the sensation that it is morning, using all sorts of silly words. I might point out that it was cold. I might mention dew. I might mention birdsong or make some fatuous observation about flowers that have closed up for the night (I know nothing about flowers beyond Ophelia's last scene, Lycidas and Ode to a Nightingale), and all to try to describe to the reader that incommunicable earliness of everything.
But then Flann O'Brien comes along and draws away the veil, slices through the budding verbal vegetation and simply says "There was an incommunicable earliness about everything.
I believe, too, that this was how Flann O'Brien must have approached the problem. It is (for various reasons) terribly important in the novel that no time has passed and it is still early morning (they have been outside time), but it is also important that nobody should have a watch by which to measure things. Even the sun must be avoided, as certainties are anathema to the whole theme of The Third Policeman. So I imagine him jotting down a few pointers - dew, flowers, mists - and becoming frustrated. Then he gives up. He decides to write instead of "the incommunicable earliness" and he uses that word - incommunicable - precisely because he feels defeated.
Yet it works. I know precisely what he means. He has cut away the inventive aspect of writing and instead is telling, and telling works perfectly.
What rule can be learnt from this by the ardent student of fiction? Tell, don't show.
'Your talk,' I said, 'is surely the handiwork of wisdom because not one word of it do I understand.'
The Inky Fool pondering The Third Policeman
P.S. Ransacking that book to find the quotation reminded me of what a splendid novel it is. All should read it: Amazon link here.