首楞嚴義疏注經 5.349

5.349

初觀身心，唯見煖觸，後觀煖氣，無相無生。我身自空，煖依何住？身心既寂，性火妙發，故云神光內凝成智慧火。

Initially contemplating body and mind, he saw only the sensation of warmth; later contemplating the warm energy, it was markless and non-arising. If my body itself is empty, on what does warmth abide? Body and mind having become quiescent, the wondrous nature of fire flared up; hence it says 'the spiritual light congealed within, turning into the fire of wisdom'.