法華義疏 12.77

12.77

若未入火而稱名得脫者，或謂不必是觀音力；今入火不燒，必知是菩薩力。

If one escaped by reciting the name before entering the fire, someone might think it was not necessarily the power of Avalokiteśvara; now, entering fire without being burned, one will certainly know it is the power of the bodhisattva.