Natyashastra
वक्षसोऽष्टाङ्गुलस्थौ तु प्राङ्मुखौ खटकामुखौ । समानकूर्परांसौ तु चतुरस्रौ प्रकीर्तितौ ॥ १८५॥
The two Kaṭakāmukha hands are held at a distance of eight Aṅgulīs from the chest, facing forward. These are known as Caturasra when their palms are parallel and their fingers are in a similar position.
english translation
vakSaso'STAGgulasthau tu prAGmukhau khaTakAmukhau । samAnakUrparAMsau tu caturasrau prakIrtitau ॥ 185॥
hk transliteration by Sanscript