《资治通鉴·后汉纪·后汉纪二》
当初，后汉高祖和吏部尚书窦贞固同在后晋高祖处供事，互相深知敬重，待后汉高祖当了皇帝，想任命窦贞固为宰相，他问苏逢吉道： 你之外，有谁能作宰相？ 
初，帝与吏部尚书窦贞固俱事晋高祖，雅相知重，及即位，欲以为相，问苏逢吉： 其次谁可相者？ 
Initially, Later Han Gaozu and Minister of Personnel Dou Zhenggu served the Later Jin Gaozu together, deeply understood and respected each other. When Later Han Gaozu became the emperor, he wanted to appoint Dou Zhenggu as prime minister, and he asked Su Fengji: Besides you, who else can be prime minister?