Bodhayana is considered to have written an extensive "vritti" (commentary) on the Purva and Uttara Mimamsas. Tanka is attributed with having written commentaries on Chandogya Upanishad and Brahma Sutras. Nathamuni of the ninth century AD, the foremost Acharya of the Vaishnavas, collected the Tamil prabandhas, classified them, made the redaction, set the hymns to music and spread them everywhere. He is said to have received the divine hymns straight from Nammalvar, the foremost of the twelve Alvars, by yogic insight in the temple at Alwar Thirunagari, which is located near Tirunelveli in South India. Yamunacharya renounced kingship and spent his last days in the service of the Lord at Srirangam and in laying the fundamentals of the Vishishtadvaita philosophy by writing four basic works on the subject.