Natyashastra

siva.sh/natyashastra/9/71

[श्रवणाभ्यासे वक्रा विजृम्भणा वाक्यरूपणावसरे ॥] मेति वदेति च योज्या प्रसारितोत्कम्पितोत्ताना ॥ ७१॥

sanskrit

When curved near the ear, the Sūcīmukha hand should represent listening intently. In a yawning gesture, it should indicate speech articulation. To signify expressions such as ‘No’ or ‘Speak,’ the forefinger should be stretched, shaken, and moved upwards.

english translation

[zravaNAbhyAse vakrA vijRmbhaNA vAkyarUpaNAvasare ||] meti vadeti ca yojyA prasAritotkampitottAnA || 71||

hk transliteration by Sanscript