This Too Shall Pass

 A powerful king, ruler of many domains, was in a position of such magnificence that wise men were his mere employees. And yet one day he felt himself confused and called the sages to him.

He said:
'I do not know the cause, but something impels me to seek a certain ring, one that will enable me to stabilize my state.

'I must have such a ring. And this ring must be one which, when I am unhappy, will make me joyful. At the same time, if I am happy and look upon it, I must be made sad.'

The wise men consulted one another, and threw themselves into deep contemplation, and finally they came to a decision as to the character of this ring which would suit their king.

The ring which they devised was one upon which was inscribed the legend:

This, too, Shall Pass.

Source: http://www.katinkahesselink.net/sufi/stories.html