It's the last eight lines of the poem:

If you have honour to spare, employ it on the living;
The dead are as dead as Nineteen-Thirty-Eight.
Sleep to the noise of running water
To-morrow to be crossed, however deep;
This is is no river of the dead or Lethe,
To-night we sleep
On the banks of Rubicon -- the die is cast;
There will be time to audit
The accounts later, there will be sunlight later
And the equation will come out at last.

...from Autumn Journal, part XXIV

Thanks to Belmont Club for the quick transcription.