O thou whose face hath felt the Winter's wind,
Whose eye has seen the snow-clouds hung in mist
And the black elm tops 'mong the freezing stars,
To thee the spring will be a harvest-time.
O thou, whose only book has been the light
Of supreme darkness which thou feddest on
Night after night when Phoebus was away,
To thee the Spring shall be a triple morn.
O fret not after knowledge -- I have none,
And yet my song comes native with the warmth.
O fret not after knowledge -- I have none,
And yet the Evening listens. He who saddens
At thought of idleness cannot be idle,
And he's awake who thinks himself asleep.

John Keats

http://www.poemhunter.com/poem/what-the-thrush-said-lines-from-a-letter-to-john-hamilton-reynolds/