佛祖歷代通載 13.49

13.49

（三十六　癸巳）　西蕃寇圍涼州。帝命三藏不空祈陰兵救之。空誦仁王密語數番。有神介冑而至。帝親見之。問曰。神謂誰。空曰。北方毘沙門天王長子也。空誦密語遣之。數日涼州捷報。有神兵至威武雄盛。賊畏懼卷甲而去。帝悅詔天下。軍壘皆立毘沙門天王祠。

([Year] thirty-six, guisi [753 CE]) Western Tibetan invaders besieged Liangzhou. The Emperor commanded Tripiṭaka Master Amoghavajra to pray to the unseen troops for rescue. Amoghavajra recited the secret words of the Benevolent Kings [Sūtra] several times. A spirit clad in armor and helmet arrived, and the Emperor saw him in person. The Emperor asked, "Who is this spirit?" Amoghavajra said, "He is the eldest son of Vaiśravaṇa, Heavenly King of the North." Amoghavajra recited the secret words and dispatched him. A few days later, a victory report arrived from Liangzhou: spirit soldiers had arrived with formidable and flourishing martial power, and the bandits, struck with dread, rolled up their armor and retreated. The Emperor, delighted, issued an edict to the empire commanding that shrines to Heavenly King Vaiśravaṇa be established at all military encampments.