Natyashastra
हस्तौ तथैव कर्तव्यौ कटीनाभितटस्थितौ । दक्षिणो नाभिसंस्थस्तु वामः कटितटस्थितः ॥ ७॥
Similarly, the two hands should be positioned at the region between the waist and the navel, the right hand placed near the navel, and the left hand at the left side of the waist.
english translation
hastau tathaiva kartavyau kaTInAbhitaTasthitau । dakSiNo nAbhisaMsthastu vAmaH kaTitaTasthitaH ॥ 7॥
hk transliteration by Sanscript