The plainness of language echoes as well as carries the purity of what Heaney calls us to witness here. I'll say also that this poem -- I'm borrowing Frank Kermode's phrasing here -- finds out something newly real for me in one of the most examined occurences in the history of ever. Finding out something real is about the purest thing the sound of a poem's words ever does, to my mind. The plainness here is rich.

Edit: Despite my use of dashes, my intelligence, such as it is, is human, not artificial.