The Śrīemat Rahasyatrayasāra (‘The Auspicious Essence of the Three Mysteries’) by Vedānta Deśika (or Veṇkaṭanāta, 1268-1369) is a kind of summa theologiae that proceeds largely by exegeting the three holy mysteries or mantras (tirumantra, dvayamantra, and caramaśloka [Bhagavadgītā, 18.66]) cherished by the south Indian Śroevaiṣṇava tradition. The Rahasyatrayasāra is a comprehensive presentation of Śroevaiṣṇava exegesis, philosophy, theology, practice and religious sociology, all woven into a single treatise expressive of what it means to believe and practice the truths and values inscribed in the mantras as read by Śroevaiṣṇavas. The Guruparaṃparāsāra is an additional, introductory chapter prefixed to the Rahasyatrayasāra, of no more than several thousand words.
In this essay I examine the Śroevaiṣṇava understanding of tradition by a close reading of the Guruparaṃparāsāra, attending to the content and style, as well as the sources cited in the text and its commentarial heritage. The Guruparaṃparāsāra offers an intracommunity rationale for the Śroevaiṣṇava choice of founding the tradition in the person of the ācārya, succinctly arguing that the student/reader should mindfully recollect the lineage of Śroevaiṣṇava ācāryas whenever beginning to study the mantras and related religious topics. As an articulate presentation of tradition by an important Indian intellectual, it is also a resource for understanding tradition more widely in India.
For the most part, I read the Guruparaṃparāsāra on its own, even if it can and ultimately should be read also in relation to the Rahasyatrayasāra and to others among Deśika's works, such as the Saṃpradāyapariśuddhi.