The Yogis achieve the nectar of equality solely through Samadhi.
The lamp of wisdom does not appear without Yoga practice, just as the fire latent in the sacrificial wood does not appear without churning.
Outside, a vessel's fire does not provide light. When the hull is shattered, however, the light shines from the outside.
The vessel refers to one's physical form. The light or fire inside is the seat of "That." When the body is split by the teachings of a Guru, the light of Brahmajnana shines brightly.
With the Guru as the helmsman and through the affinities of Abhyasa, one passes the subtle body and the ocean of Samsara.