500 words analysis of a book

For this forum, please choose an image or symbol that you feel Li-Young Lee repeats throughout his book of poems.  With your choice of "motif," please explain how the poet builds on his meaning every time the image/symbol is repeated.  Please use specific examples from several poems to support your ideas!

the link of the book

https://books.google.com/books?id=OXYpUlu5CJMC&pg=PA7&source=gbs_selected_pages&cad=2#v=onepage&q&f=false