Prasāda — Divine Grace and the Sanctified Remnant of Bhagavān
Prasāda (from the Sanskrit root pra + sad, 'to sit/settle in, to become clear/serene/gracious') carries two intertwined meanings in Śrī Vaiṣṇava theology. At the philosophical level, prasāda is Bhagavān's grace — the spontaneous, unconditional, self-motivated favour (anugraha) that Bhagavān shows toward the surrendered soul. This grace does not depend on the recipient's merit (karma) or spiritual qualification; it arises from Bhagavān's own svabhāva (innate nature) as sarva-loka-śaraṇya (the refuge of all worlds) and śaraṇāgata-vatsala (one who is tenderly disposed toward those who have surrendered). The Śrī Vaiṣṇava Āchāryas — particularly Piḷḷai Lokāchārya in the Śrīvacana Bhūṣaṇam — stress that prasāda-grace is asymmetrically powerful: it can overcome karma, annul past sins, and accelerate liberation in ways that no amount of the jīva's own effort (sva-prayatna) can match.
At the practical/ritual level, prasāda is any material item — most commonly food (naivedyam), water (tīrtham/caraṇāmṛtam), tulasī leaves, flowers, garlands, or the śatāri (Āzhvār's crown placed on the head at the temple) — that has first been offered to Bhagavān and then returned to the devotee. The act of offering transforms the item: it has 'touched' Bhagavān (in the sense of coming into contact with His divine presence in the icon, or being offered with mantra before Him), and so it carries His divine touch back to the recipient. Accepting prasāda is therefore a form of receiving Bhagavān's direct grace — His very presence transmitted through the sanctified medium. This is why Śrī Vaiṣṇavas receive prasāda with both hands cupped together and bring it to the head first before consuming.
In the temple context, prasāda forms a complete circuit of devotion: the devotee brings fresh food (uncooked or cooked) as an offering (naivedyam), it is offered before the arcā (consecrated icon) with Vedic mantras by the priest, it is 'accepted' by Bhagavān (theologically, the divine presence partakes of the essence), and then the material remainder is distributed as prasāda to all present. This circuit of offering-and-return enacts the Śrī Vaiṣṇava theology of kaiṅkarya (service) and svāmitva (Bhagavān's ownership): the devotee offers what is already Bhagavān's, and Bhagavān graciously returns it sanctified. Maṭha prasāda (from Āchārya mutt kitchens) carries the additional significance of the Āchārya's own kaiṅkarya being embedded in it.
[From alternate entry: prasadam]
The Grace Made Edible
Prasādam (Sanskrit: prasāda = grace, clarity, favour) is the consecrated food — or any consecrated object — that has been received by Bhagavān during worship (naivedyam) and is then distributed to devotees. In the Śrī Vaiṣṇava tradition, prasādam is not merely 'food that was offered' but the actual remnants of what Bhagavān has accepted and blessed — śeṣam ('the remainder/that which was left by the Master').
Śeṣam
The Tamil/Sanskrit pair prasādam-śeṣam expresses the same reality from two angles: prasādam from the giving side (Bhagavān's grace expressed as food), śeṣam from the receiving side (we are His servants eating what He has left). Receiving prasādam purifies the devotee — it is a direct transmission of Bhagavān's grace into the body.
Extension to Āzhvārs and Ācāryas
In the sampradāya, prasādam extends beyond food offered to the temple deity. The remnants of food eaten by a revered Āzhvār, Ācārya, or bhāgavata (devotee) are equally considered prasādam — tadīya śeṣam. Receiving such prasādam is considered highly auspicious.