In The Waste Land, Eliot uses quotation to decentralize the poem's authority. Much of the poem's message is not present in the central text, but is scattered throughout numerous classical allusions and references. Eliot deliberately obscures any central theme or coherent message in the poem with tangential references and margenalia. Eliot constructs his poem from the fragments of the exploded past culture, crafting a wasted land of reconfigured shards which would become the background of modernity.
One reference that stood out to me was in lines 99-100, referring to the myth of Tereus and Philomela. Understanding the brutal context behind Philomela's rape and mutilation definitely added meaning to the poem for me; Eliot includes a symbol of violence and suppression to illustrate the stifling effect World War 1 had on English culture. The myth also served as the basis for Shakespeare's Titus Andronicus. I think Eliot uses this reference to indicate how other authors have reworked antiquity to suit their own creative vision. By melding so many different references into one work, Eliot is in many ways continuing the storytelling tradition of appropriating and retelling old stories, albeit with a distinctly modern twist on them.