Oppilā Appan — The Incomparable Lord of Tiruviṇṇagaram
The deity of Tiruviṇṇagaram, near Kumbakonam and Tirunāgeśvaram, is traditionally praised as Oppilā Appan—the Lord who has no equal. In popular Tamil usage the name also came to be heard as Uppu-illā Appan, 'the Lord without salt,' in connection with the temple’s distinctive rule that naivedya is prepared without salt. The primary theological name and the salt-free temple tradition should both be retained rather than reducing the name to a single folk etymology.
The sthala-purāṇa relates that Bhūmi Devī appeared as the daughter of Sage Mārkaṇḍeya. When Bhagavān came seeking her hand, the sage expressed concern that the young girl did not yet know how to cook properly and might even omit salt. Bhagavān declared that He would gladly accept food without salt and married her. In remembrance of this assurance, offerings at the temple are prepared salt-free.
The teaching is not that ritual care is irrelevant, but that Bhagavān’s saulabhya and affection are manifest in His willing acceptance of the service offered by Bhūmi Devī and Mārkaṇḍeya. Tiruviṇṇagaram is a Divya Desam praised by the Āzhvārs, and the Lord stands with Bhūmi Devī beside Him.
The temple is in the Kumbakonam–Tirunāgeśvaram region of present-day Thanjavur district, not near Nagapattinam. The salt-free prasāda is a distinctive rule of this temple and should not be generalized as a custom of unrelated temples.