Natyashastra
खेदो भवेत्प्रयोक्तॄणां प्रेक्षकाणां तथैव च । खिन्नानां रसभावेषु स्पष्टता नोपजायते ॥ १५९॥
The performers and the spectators would be tired. When they are tired, the clear manifestation of sentiments and emotions does not take place.
english translation
khedo bhavetprayoktRRNAM prekSakANAM tathaiva ca । khinnAnAM rasabhAveSu spaSTatA nopajAyate ॥ 159॥
hk transliteration by Sanscript