釋氏稽古略 4.161

4.161

西夏趙元昊。夏四月遣使來宋稱臣請和。又復遣使稱男不稱臣。但稱臣於契丹（宋鑑）。

Zhao Yuanhao of the Western Xia sent an envoy to Song in the fourth month of summer, declaring himself a vassal and requesting peace. He then sent an envoy again, calling himself “son” rather than “vassal,” while declaring himself a vassal only to the Khitans (Songjian).