《资治通鉴·唐纪·唐纪三十六》
己丑，唐朝任命回纥叶护为司空，封忠义王爵，并答应每年赠送回纥丝织品二万匹，让他们到朔方军受取。
己丑，以回纥叶护为司空、忠义王；岁遗回纥绢二万匹，使就朔方军受之。
On Ji Chou, the Tang court appointed Huihe's Yehu as Minister, bestowed on him the title of loyal and righteous king, and promised to give Huihe 20,000 bolts of silk each year, which they were to receive at the Shuofang Military.