It is related that Ibn es Semmak[FN#162] went in one day to Er
Reshid and the Khalif, being athirst, called for drink. So his
cup was brought him, and when he took it, Ibn es Semmak said to
him, "Softly, O Commander of the Faithful! If thou wert denied
this draught, with what wouldst thou buy it?" "With the half of
my kingdom," answered the Khalif; and Ibn es Semmak said, "Drink
and God prosper it to thee!" Then, when he had drunken, he said
to him, "If thou wert denied the going forth of the draught from
thy body, with what wouldst thou buy its issue?" "With the whole
of my kingdom," answered Er Reshid: and Ibn es Semmak said, "O
Commander of the Faithful, verily, a kingdom that weigheth not in
the balance against a draught [of water] or a voiding of urine is
not worth the striving for." And Haroun wept.