A king asked one of the highly talented craftsmen to present a sample of his best craftsmanship such that he himself would not be able to create anything more remarkable than that. The king also asked another highly skilled craftsman to present a sample of his best craftsmanship. The king put a curtain between the two.
The first craftsman built a wall and decorated it to the highest quality of the art and prepared a masterpiece of the highest level of human skill. The second craftsman erected a wall without any decoration. The wall was very clear, polished that exceeded a clear mirror in its burnish.
The king asked the first craftsman to present his creation. The craftsman presented wall decorated with beautiful artwork. All present were spellbound to see the masterpiece. The king then asked the second craftsman to show his work. The second craftsman requested the king to remove the curtain between the two sections. The king had the curtain removed. People saw that there was an exactly similar wall standing on the other side as the first craftsman had raised as, due to the removal of the curtain, the decorations of the first wall appeared on the second wall with absolutely no difference.
(Sirat-ul-Mahdi, Vol. 1, p. 275–276, 2008 edition)