The Naalayira Divya Prabhandham are 4,000 verses in Tamil spoken by ancient Tamil Vaishnava saints (Alwars) that are revered by Sri Vaishnavas.
They are so important that they are epistemologically considered equivalent to the Vedas in terms of their validity. Sri Vaishnava acharyas routinely cite verses from the Prabhandham to support their philosophical and theological doctrines.
My question is, what is the Pramanya for this?
Shabaracharya's commentary on the Purva Mimamsa Sutras is traditionally considered to establish the Pramanya of the Vedas, and Yamunacharya's Agama Pramanya is traditionally considered by Sri Vaishnavas to establish the Pramanya of the Pancharatra Agamas.
So is there something similar that establishes the Pramanya of the Naalayira Divya Prabhandham?