A nonsense rhyme about a 'wondrous wise' man who scratches his eyes out on a bramble bush, then scratches them back in on a second one. The daftness is the whole point.
From Mother Goose / Nursery Rhymes (traditional). See the whole collection.
There was a man in our town,
And he was wondrous wise,
He jumped into a bramble bush,
And scratched out both his eyes;
But when he saw his eyes were out,
With all his might and main,
He jumped into another bush,
And scratched 'em in again.
Public domain. Text from The Real Mother Goose (Blanche Fisher Wright, 1916), via Project Gutenberg. View the source edition