Sat-sampradāyam — The True Tradition
Sat-sampradāyam (Sanskrit: sat — good/true/existent; sampradāya — tradition/transmission) refers to the authentic, divinely-originated tradition of teaching that flows unbroken from Nārāyaṇa through Lakṣmī, through the Āzhvārs, and through the chain of Āchāryas down to the present. It is distinguished from asat-sampradāya — traditions that have deviated from or corrupted the original teaching.
In Śrī Vaiṣṇavam, the sat-sampradāyam is the Ubhaya-Vedānta tradition: founded on both Sanskrit Vedas and the Tamil Divya Prabandham as co-equal authorities. The sat-sampradāyam is also called srivaishnava-sampradayam and its propagators are sat-sampradāya pravarthakas.
In Yathīndra Pravaṇa Prabhāvam, Māmunigaḷ's role is precisely to preserve and propagate the sat-sampradāyam against the incursions of kudṛṣṭis and those who would dilute the tradition. His establishment of āchārya-niṣṭhā as the culmination of the sat-sampradāyam is the text's central theme.