Natyashastra
सस्वनरुदितैर्मोहागमैश्च परिदैवतैर्विलपितैश्च । अभिनेयः करुणरसो देहायासाभिघातैश्च ॥ २॥
With loud weeping, fainting, and lamentations, The Karuna rasa is to be acted out with physical exhaustion and blows.
english translation
sasvanaruditairmohAgamaizca paridaivatairvilapitaizca । abhineyaH karuNaraso dehAyAsAbhighAtaizca ॥ 2॥
hk transliteration by Sanscript