A Passage to India - Life Between Worlds

There's a wondeful passage that seems to define life as a transcient trifle where what is really important is the snatching and appreciation of moments of beauty, for it is beauty that characterises this quick burst of humanity and makes it beyond bearable, but enjoyable:

'The poem had done no 'good' to anyone, but it was a passing reminder, a breath from the divine lips of beauty, a nightingale between two worlds of dust. Less explicit than the call to Krishna, it voiced our loneliness nevertheless, our isolation, our need for the Friend who never comes yet is not entirely disproved.' - p.119

Religion vs Beauty. It recalls a particular metaphor in a poem I can't for the life of me recall where life is reduced to a bird flying in from the cold to enjoy the warmth and tremendous excitement of a festive feast in an instant before exiting through another open window. Two worlds of dust separated by life.

If anyone knows the poem, please put me out of my misery, there's a connection awaiting conclusion.