Hekayat 6 from Chapter 4 of Golestan of Saadi Shirazi

Sahban Wa'il was regarded as unparalleled in eloquence because he would speak for an entire year before an audience without repeating a single word. And if repetition occurred, he would express it in a different way. Among the courtesies expected of the companions of kings, this is one of them.

Though speech may be charming and sweet,
Worthy of praise and approval,

Once it is said, do not repeat it again,
For just like with sweets, once is enough.

سحبان وائل را در فصاحت بی نظیر نهاده‌اند به حکم آن که بر سر جمع سالی سخن گفتی لفظی مکرّر نکردی، وگر همان اتفاق افتادی به عبارتی دیگر بگفتی. وز جمله آداب ندماء ملوک یکی این است.

سخن گرچه دلبند و شیرین بود

سزاوار تصدیق و تحسین بود

چو یک بار گفتی مگو باز پس

که حلوا چو یک بار خوردند بس