What is the poet's purpose written this poem, Gitanjali [67]?

Rabindranath Tagore - Gitanjali [67]

Thou art the sky and thou art the nest as well.

O thou beautiful, there in the nest it is

thy love that encloses the soul with colours

and sounds and odours.

There comes the morning with the golden

basket in her right hand bearing the wreath of

beauty, silently to crown the earth.

And there comes the evening over the lonely

meadows deserted by herds, through trackless

paths, carrying cool draughts of peace in her

golden pitcher from the western ocean of rest.

But there, where spreads the infinite sky for

the soul to take her flight in, reigns the stainless

white radiance. There is no day nor night, nor

form nor colour, and never, never a word.