《资治通鉴·唐纪·唐纪五十二》
僧人延素被吐蕃俘获后，有个叫做徐舍人的吐蕃将领对延素说： 我是英国公李的五世玄孙。
僧延素为虏所得。虏将有徐舍人者，谓延素曰： 我英公之五代孙也。
After the monk Yan Su was captured by the Tubo, a Tubo general named Xu Sheren said to Yan Su: I am the fifth-generation great-grandson of Duke Yingguo Li.