On his journey of pilgrimage to India, Xuanzang 玄奘 was detained for more than a month in Gaochang 高昌. During his period of custody, Qu Wentai 麴文泰, the king, requested Xuanzang to expound the Renwang sūtra 仁王経, famous for national protection. Xuanzang accepted this invitation, and spent a month to expound this sūtra. In terms of social atmosphere, both China and Gaochang promoted the sūtra. In the case of the king himself, he both believed in this sūtra and felt the need for Buddhism to alleviate the crisis in Gaochang. In the case of Xuanaang, before his journey to the west, he was already familiar with the sūtra, and had the knowledge to expound it. In the commentary of this sūtra written by Yuance 円測, one of Xuanzang’s disciples, we can get a clue to reconstruct what Xuanzang expounded in Gaochang.
