那罗延，在早期印度神话体系中是原人那罗之子，在后来的婆罗门教，特别是毗湿奴派的文献中，日益将那罗延与毗湿奴——黑天完全等同起来。佛教兴起以后，原为婆罗门教三大神之一的毗湿奴即那罗延，被"收编"为佛教的护法神，在汉译佛经中那罗延还被意译为"金刚力士"或"钩锁力士"，并被用于佛或菩萨的名号。魏晋隋唐时期中土流传着那罗延信仰，希冀获得那罗延神力、对那罗延身的向往、修持那罗延秘法、以那罗延为法名、朝觐那罗延窟圣迹、造像等是当时最主要的信仰形式。

In early Indian mythology， Nryana was the son of Purusha Nara. In later Brahmanism， especially in the texts of Vaishnava，Nryana gradually became identical with Visnu-Krsna. After the rising of Buddhism，Visnu（Nryana），as one of the three main gods in Brahmanism，was “ absorbed”as a guardian of Buddhism. In some Chinese sutras，“ Nryana”has been translated as “ Vajra Giant”or “ Hooklock Giant”and used to refer to Buddha or Bodhisattva. It was very common for people had faith in Nryana in the Weijin， Sui and Tang Dynasties in China. To get the supernatural force of Nryana， people conducted religious behaviors such as practicing the esoteric teachings of Nryana，using Nryana as their religious names，going on a pilgrimage to the holy site of Nryana Cave and making statues of Nryana.