In The Name of Allah, The Most Merciful, The Bestower of Mercy.

One day Ibn As-Sammaak [may Allah have mercy upon him] came when Haaroon Ar-Rasheed [may Allah have mercy upon him] asked for water. After a cup of cold water was brought, he said to Ibn As-Sammaak, “Admonish me”. Ibn As-Sammaak said to him, “O leader of the believers! How much would you pay for this drink if you were deprived of it?” He replied, “Half of my reign”. Ibn As-Sammaak said to him, “Drink, may it be blessed”. After he drank, Ibn Sammaak said to him, “If this water was prevented from exiting your body, then how much would you pay for it (to be removed)”, he said, “The other half of my reign”. Ibn Sammaak said to him, “Indeed, half of the reign is the value of a little drink of water and the value of the other half is that of urine. It is befitting that you do not strive and compete with others for it”. Haaroon wept.

An Excerpt from Al-Bidaayah Wan-Nihaayah. 10/213-217