An allegory is a literary device in which a character, place or event is used in order to deliver a much broader message. Allegories allow readers to illustrate or convey complex ideas in simple, imaginative ways.
The central theme of this poem is life and death, and this is conveyed through the use of allegory. In this poem, the allegory is build up through the comparison of man and the swan. Rilke talks about how the swan is awkward when he walks on land, always unstable. This is compared to how man is throughout his life. Rilke contniues the allegory by explaining how a swan looks when he lets go of land and jumps into the water. On water, the swan is pleased to be carried, and needs little effort to be at peace. This is compared to the transition of man to death.