This is a translation of the poem ‘The God Abandons Antony’ by the Greek poet C. P Cavafy:

When suddenly, at midnight, you hear
an invisible procession going by
with exquisite music, voices,
don’t mourn your luck that’s failing now,
work gone wrong, your plans
all proving deceptive—don’t mourn them uselessly.
As one long prepared, and graced with courage,
say goodbye to her, the Alexandria that is leaving.
Above all, don’t fool yourself, don’t say
it was a dream, your ears deceived you:
don’t degrade yourself with empty hopes like these.
As one long prepared, and graced with courage,
as is right for you who proved worthy of this kind of city,
go firmly to the window
and listen with deep emotion, but not
with the whining, the pleas of a coward;
listen—your final delectation—to the voices,
to the exquisite music of that strange procession,
and say goodbye to her, to the Alexandria you are losing.

(source: http://www.cavafy.com/poems/content.asp?id=12&cat=1)

Evidently, Jacqueline Onassis was very fond of Cavafy’s work, and requested another of his poems, Ithaca, be read at her funeral.