In the first stanza it is saying the he broke the spell that held him and the witchery of song. The next line means the poet's lacking knowledge and waste my importance of years and will not waste any more. In the next line it is saying that for poetry, greatly born and consorts with poorness and reject. In the second stanza it is saying he broke the spell, but did not hold its power and could restrain me another hour. The next line means ah, no thought! how could I forget and that his source of inspiration was nature smiling at him. In the third stanza it is saying that poetry still came to remain on his sight and the nature he sights. The next line means the source of the stars and sun and that nature and poetry are one. In the next line it is saying that poetry and everything surrounding him and part of the poetry that has held him in the spell, and that poetry has brought me back and I love it.
Through out the poem, poetry is a spell that is holding him. He can't escape the spell, because poetry is everywhere around him. Also, In the poem there is figurative language. As it states in the poem, First stanza, first line, "I broke the spell that held me long."