As the (likely apocryphal, unfortunately) story goes: Abbasid Caliph Harun Al-Rashid had announced that if anyone brought him a poem he hadn't heard before, he'd give him the weight of whatever he wrote it on in gold. Of course there's no way he'd actually do that; as the story goes Harun Al-Rashid was able to memorize any poem after hearing it once and had a male slave who was able to memorize one after hearing it twice and a female slave who was able to memorize one after hearing it thrice. As you probably guessed, whenever a poet brought him a new poem he'd listen and just recite it back at them, bring the male slave (who at this point heard it twice) to recite it and after that have the female slave recite it, after which he'd say "see? I've heard it before" and send them back with no gold. Al-Asma'i, a prominent poet, was sure that there was a trick to it, and wrote a poem that uses strange, rare meanings and sounds such that it'd be impossible to memorize in one hearing. The opening and title of the poem is "sautu safiri lbulbuli", meaning "the sound of the bulbul's (a type of songbird) whistling".
Al-Asma'i then disguised himself as a nomad Arab and wore a face mask (as he was known to the Caliph) and hit Harun Al-Rashid with the poem, which he failed to memorize and so was unable to recite. Because of that neither of his slaves could recite it and Al-Asma'i demanded his reward, so Harun Al-Rashid asked what he wrote the poem on and Al-Asma'i replied "I carved it into a ceramic pillar I inherited from my father. The pillar is on my camel carried by ten soldiers outside". Then Harun Al-Rashid's minister says "this has to be Al-Asma'i", and he's ordered to take off his face mask. Well the funny part is over, but the rest of the story says that Al-Asma'i gives back the money he took but in return Harun Al-Rashid would hold his promise with the other poets.
As y'all probably noticed the story is full of holes, but hey, a man can dream.
Here's an English translation
The sound of whistling bulbul
Excited my tipsy heart
Water and roses coming together
With the flowers of the glance of her black eyes
And you, my dear sir
My master and my lord
Oh, how I have wished for
A ruby-cheeked fawn
One that I plucked from a cheek
Having kissed it until shyness turned it pink
And she said: No, no, no, no
And ran away
And the pretty woman swooned over
Because of what this man had done
And she shouted in surprise
Oh my, oh dear, oh dear me
And I said, don’t you shout
Show me the pearls
That’s when she told him
Get up and get the drinks
And a group of servants who offered me
A wine that tastes like honey
I smelled it with my nose
More fragrant than cloves
In the midst of a beautiful garden
Full of flowers and filling me with joy
And the approaching flute going drin, drin
And the drum going pa rum pum pum
Rum pum pum, rum pum pum
Rum pum pum, rum pum pum
And the roof* making a sak-sak sound
And I enjoyed the dancing
Come on, come on, come on
Come on, come on, come on
And grilled meat, fit for a king
On papers made of quince tree leaves
And the turtle dove sang
More and more
If you only you’ve seen me riding
A scrawny donkey
Walking on three legs
Like a limping man
And people were throwing
Pots at my camel in the market
And everyone was scaring me
Behind me and around me
But I walked on and fled
Afraid of getting killed
To meet a king
Dignified and sublime
Who ordered a gift of clothing for me
Red like blood
I drag it behind me as I walk
Proud of its long tail
I’m the brilliant poet
From a neighborhood in Mosul
I’ve composed adorned pieces of poetry
Unattainable for other poets
I say at the start of it:
The sound of whistling bulbul
Come on, come on, come on
and a link in case anyone wants to listen to it.
*The translation I found says this and while it's probably wrong I actually have no idea what it's supposed to be. I think it's a musical instrument of some sort.