What image does the poet use to describe the beautiful bounty of the earth?

John Keats uses various images to describe the many beautiful things existing on the earth. The sun, the moon, shady trees, the beautiful daffodils, small streets of clear water, forest brake, musk-roses etc. And then, there is this striking image of nature as an endless fountain pouring into us a heavenly immortal drink i.e. nectar and thus keeping us in a constant state of joy.