Exhalation - Stories

How much do I want to read more? 6/10

This is clearly weird and SF. A merchant build a mirror to go back 20 years in time, and being able to have a conversation with one's previous self.
He's about to tell a story of a man who had such an experiement.

The merchant and the alchemist's gate

My name is Fuwaad ibn Abbas, and I was born here in Baghdad.
My father was a grain merchant.

“I have recently built something that may change your opinion. You would be the first person I have shown it to. Would you care to see it?”
“Please observe,” he said.
Bashaarat thrust his arm through the hoop from the right side, but it did not extend out from the left. Instead, it was as if his arm were severed at the elbow, and he waved the stump up and down, and then pulled his arm out intact.
I had not expected to see such a learned man perform a conjuror’s trick, but it was well done, and I applauded politely.
“Now wait a moment,” he said as he took a step back.
I waited, and behold, an arm reached out of the hoop from its left side, without a body to hold it up. The sleeve it wore matched Bashaarat’s robe. The arm waved up and down and then retreated through the hoop until it was gone.
The first trick I had thought a clever mime, but this one seemed far superior, because the pedestal and hoop were clearly too slender to conceal a person. “Very clever!” I exclaimed.

“Is this sorcery?” I asked.
“You have created something truly astonishing.”
“but this is merely a prelude to what I intended to show you.”
"The two sides of the doorway are separated by a span of twenty years"
I was looking at a different room from the one I stood in.
“You are seeing the room twenty years from now,” said Bashaarat.
“And you say I could step through?” I asked.
“You could. And with that step, you would visit the Baghdad of twenty years hence. You could seek out your older self and have a conversation with him. Afterward, you could step back through the Gate of Years and return to the present day.”

“What did they learn when talking to their older selves?”
“Each person learns something different. If you wish, I can tell you the story of one such person.”