By chance, I finally picked up Auden's Collected Poems yesterday. Doubtless the book was only in the ill-tended poetry section for his anniversary.
A selection fit for Ash Wednesday:
"O let not Time deceive you,
You cannot conquer Time.
"In the burrows of the Nightmare
Where Justice naked is,
Time watches from the shadow
And coughs when you would kiss.
"In headaches and in worry
Vaguely life leaks away,
And Time will have his fancy
To-morrow or to-day."
As I Walked Out One Evening, November 1937
Memento homo quia pulveris es et in pulverem reverteris!