This one by Dannie Abse:

They held up a stone.
I said, ‘Stone.’
Smiling they said, ‘Stone.’

They showed me a tree.
I said, ‘Tree.’
Smiling they said, ‘Tree.’

They shed a man’s blood.
I said, ‘Blood.’
Smiling they said, ‘Paint.’

They shed a man’s blood.
I said, ‘Blood.’
Smiling they said, ‘Paint.’