Natyashastra
पथि चरणरचनरञ्जनरङ्गणकरणान्यधोमुखेनैव । ऊर्ध्वमुखेन तु कुर्यात् दष्टं शृङ्गं च लेख्यं च ॥ ४०॥
With its fingers pointing downward, this hand should be used to represent showing the way, decorating the feet, and crawling. With its fingers pointing upward, it should indicate biting, a horn, and writing.
english translation
pathi caraNaracanaraJjanaraGgaNakaraNAnyadhomukhenaiva । Urdhvamukhena tu kuryAt daSTaM zaRGgaM ca lekhyaM ca ॥ 40॥
hk transliteration by Sanscript