The Brahma-saṁhitā, chapter five, verse 46, states that the viṣṇu-tattva, or the principle of the Absolute Personality of Godhead, is like a lamp because the expansions equal their origin in all respects. A burning lamp can light innumerable other lamps, and although they will not be inferior, still the lamp from which the others are lit must be considered the original. Similarly, the Supreme Personality of Godhead expands Himself in the plenary forms of the viṣṇu-tattva, and although they are equally powerful, the original powerful Personality of Godhead is considered the source. This example also explains the appearance of qualitative incarnations like Lord Śiva and Lord Brahmā. According to Śrīla Jīva Gosvāmī, śambhos tu tamo-’dhiṣṭhānatvāt kajjalamaya-sūkṣma-dīpa-śikhā-sthānīyasya na tathā sāmyam: “The śambhu-tattva, or the principle of Lord Śiva, is like a lamp covered with carbon because of his being in charge of the mode of ignorance. The illumination from such a lamp is very minute. Therefore the power of Lord Śiva cannot compare to that of the Viṣṇu principle.”