The Mode of Divine Incarnation
Vibhava ('manifestation,' 'power,' from vi + bhava = special becoming/being) is the Pañcarātra category for the Lord's avatāras — His historical descents into the world in specific forms for specific purposes. The vibhava-avatāras include the Daśāvatāras (ten primary avatāras) and many secondary ones.
The Five Modes of Manifestation
In Pañcarātra theology, Brahman manifests in five primary modes: Para (the supreme transcendent form), Vyūha (the four cosmic emanations), Vibhava (historical avatāras), Archa (consecrated temple deities), and Antaryāmin (inner controller in all beings). The Vibhava mode is the one most familiar to devotional life — the stories of Rāma, Kṛṣṇa, Narasiṃha, Varāha, etc.
Purpose of Vibhava-Avatāra
The Lord takes vibhava forms for several declared purposes (Bhagavad Gītā 4.8): (1) paritrāṇāya sādhūnām — to protect the righteous; (2) vināśāya ca duṣkṛtām — to destroy the wicked; (3) dharma-saṃsthāpanārthāya — to re-establish dharma. Beyond these external purposes, Sri Vaishnava theology adds: the avatāra is also motivated by the Lord's inherent love (kāruṇya) and desire to be with His devotees.
Avatāra-Rahasya
A key teaching (avatāra-rahasya — the secret of the avatāra) is that the avatāra's form is not a borrowed material body but consists of śuddhasattva — the same divine, immaterial stuff as Vaikuṇṭha. The Lord is never truly 'material'; His descent is a gracious accommodation, not a genuine limitation.