佛祖統紀 42.31

42.31

二年。勅上都東都荊揚汴益等州。建寺立方等戒壇。為僧尼再度者重受戒法。五臺山建五寺。各度僧五十人。

In the second year, an imperial decree ordered that monasteries be built and Vaipulya ordination platforms erected in the Upper Capital, the Eastern Capital, Jing, Yang, Bian, Yi, and other prefectures, to readminister the ordination precepts to monks and nuns who were being re-ordained. Five monasteries were built on Mount Wutai, each ordaining fifty monks.