قصة الأصمعي وأبو جعفر المنصورA poem written during the Abassyen era .. The story behind it is that Chaliph Abu Jafaar Al Mansur made a competetion, each poet have to come up with a poem that was never said before would get the weight of that poem in gold. The Caliph brought one of his servants who used to be good in memorising poems, so whenever a poet comes and presents a poem, the servant would repeat it and say it was said before.
Al Asmai wanted to beat that, so he made this famous poem of his which is hard to memorise and he wrote it in a marbel piller and managed to over smart the Caliph
The link above has the poem as a song I just love listening to it :)