"Sarah," by Delmore Schwartz from Selected Poems: Summer Knowledge (New Directions).

Sarah

The angel said to me: "Why are you laughing?"
"Laughing! Not me. Who was laughing? I did not laugh. It was
A cough. I was coughing. Only hyenas laugh.
It was the cold I caught nine minutes after
Abraham married me: when I saw
How I was slender and beautiful, more and more
Slender and beautiful.
I was also
Clearing my throat; something inside of me
is continually telling me something
I do not wish to hear: A joke: A big joke:
But the joke is always just on me.
He said: you will have more children than the sky's stars
And the seashore's sands, if you just wait patiently.
Wait: patiently: ninety years? You see
The joke's on me!"