“. . . . Before we begin our reading, I would like to make one observation on the temporal structure of lyric poetry in general, especially in metrical schemes, as they appear in the sonnet, the canzone, the sestina, and so on. From this perspective, a poem is something that will necessarily finish at a given point: it will end after fourteen lines in the sonnet, but may be prolonged by three more lines, if the sonnet has a coda.
The poem is therefore an organism or a temporal machine that, from the very start, strains toward its end. A kind of eschatology occurs within the poem itself. But for the more or less brief time that the poem lasts, it has a specific and unmistakable temporality, it has its own time. This is where rhyme, which in the sestina consists in repeated and often rhyming end words, comes into play.”
(Giorgio Agamben, The Time That Remains: a commentary on the Letter to the Romans, p. 79, trans. Patricia Dailey)