The words of a dead manAre modified in the guts of the living. (22-23)
Auden calculates the changes that Yeats's work will undergo during this transformation. Ironically, it's a very physical description. And taken in context of Yeats's disembodied (or, well, dead) state, the image becomes all the stranger.
A few thousand will think of this dayAs one thinks of a day when one did something slightly unusual. (28-29)
Immortality isn't all it's cracked up to be, huh? Auden takes a wry look at the way the dead are truly remembered. Even someone as famous and inspirational as Yeats only gets a passing glance from most of the world.
Earth, receive an honoured guest:William Yeats is laid to rest. (42-43)
Ah, tradition. In the last section of this poem, Auden reverts to a phrasing that just about everyone has heard at some time or another. Tradition is around for a reason. It's soothing, and it helps us remember that these terrible, seemingly unprecedented losses have happened before. Other people have died, and we've found ways to mourn them – just like we'll find ways to mourn Yeats.