There are over forty commentaries on Sri Vishnu Sahasranama Stotram. The three key commentaries which are based on the Vedanta philosophy include
1. Sri Adi Sankara's commentary based on Advaita philosophy
2. Sri Parasara Bhattar, a disciple of a disciple of Sri, has written a detailed commentary popularly knows as “BHAGAVAD (GOD) GUNA (attributes) DARPANAM ( mirror)” based on Vishistaadvaita philosophy
3. Sri Sri Madhwa’s commentary based on Dvaita philosophyThis blog is based on the commentary by Sri Parasara Bhattar – Bhagavad Guna Darpanam.
Interesting incident on how Sankarar wrote the VishnuSahasranamam bhashyam. Sankarar asked one of his disciple to pick any book from the library to write commentary. The Shishya got a book and it was Vishnu Sahasranamam. Sankara sent him totally 3 times and all the three times it happen to be Vishnu sahasranamam which was happened to be the book with the disciple. So due to bhagavad sankalpam Sankarar started to write the Bhasyam for Sahasranamam of Vishnu which is one of his earlier commentaries. After which Sankarar also wrote commentary for Bhagavad Gita, Brahma Sutra etc.
Sankar’s commentary is based on advaita philosophy which claims “Gynanathala moksham”. But in the end sankarar did explain that in his BajaGovindam that “nahi nahi rakshati DukRiJNkaraNe” - “Rules of Grammar will not save you at the time of your death” and “geyaM giitaa naama sahasraM” - Regularly recite from the Gita, meditate on Vishnu [thro' Vishnu sahasranama] in your heart, and chant His thousand glories.
This explains that “Gyanam kaninda nalamana bhakthi nala moksham” – Knowledge with deep bhakthi is the route to liberation. Just knowledge will not lead one to moksham. Vishnu shasranamam is the first step in one’s bhkathi route in the path of liberation.
Brahma Sutram is full of knowledge(gyana Bhagam) and it is considered to be of knowledge. Sankarar wrote the commentary for Brahma Sutram and then he wrote the Vishnu Sahasranama Commentray which is full of bhakthi ( prema bhagam).