Natyashastra
आद्यं तु द्वादशे प्रोक्तं सन्निपातो वसानतः । एवं पातविधानं स्यात्सर्ववस्तु प्रयोजयेत् ॥ २३०॥
And at the end of the twelfth, first of all there will be Sannipāta. Thus there will be the rule of Pāta and thus one should apply all the Vastus.
english translation
AdyaM tu dvAdaze proktaM sannipAto vasAnataH । evaM pAtavidhAnaM syAtsarvavastu prayojayet ॥ 230॥
hk transliteration by Sanscript