“And O those children's voices singing in the dome!”
This is a quotation from Verlaine’s Parsifal. The poem about a knight named Parsifal who has resisted all lust and desire so he can drink from the Holy Grail. His action is exactly what Buddha’s Fire Sermon is about – free yourself from the fire of lust. Perhaps this is a sarcasm twist that Eliot intended to criticize people of modern time. People are too susceptible and vulnerable to temptation; they do not have resistance or dignity, which can be the reason why a fertile land such as Europe can turn into a Wasteland.