In the opening lines of "Spring and Fall," Hopkins uses images that call to mind some of the important themes in the poem. The falling leaves emerge as a recurring image with symbolic meaning, a motif. The first association that Hopkins draws with the falling leaves is Margaret's grief. She is crying over the leaves because they have died.
Next, Hopkins takes the association between leaves and death one step further. He compares the leaves to "the little things of man." By saying that leaves are like the things of man, he is suggesting that the fate of the leaves is similar to the fate of mankind: just as leaves inevitably die and fall, so too do all people eventually perish. Because Margaret is young and full of "fresh thoughts," she is greatly affected by these inevitable fact sof the life cycle.
The poem is called "Spring and Fall to a Young Child" by Gerard Manley Hopkins