Ramayana
प्रवर्ग्यं शास्त्रतः कृत्वा तथैवोपसदं द्विजाः । चक्रुश्च विधिवत्सर्वमधिकं कर्म शास्त्रतः ॥ १-१४-४
On performing pravargya ritual as per scriptures, like that upasada ritual too, those Brahmans have customarily performed all of those other rituals incidental to the main one scripturally. ॥ 1-14-4॥
english translation
pravargyaM zAstrataH kRtvA tathaivopasadaM dvijAH । cakruzca vidhivatsarvamadhikaM karma zAstrataH ॥ 1-14-4
hk transliteration by Sanscript