“他果然遣人來打聽了,問為何撤軍,我說大唐已經(jīng)知道他們來此,因?yàn)楸Σ蛔?故此故稅建城守城而戰(zhàn)。他并未疑心,與我相約,若是大唐閉城堅(jiān)守,要我乘夜開門,若是大唐在城下野戰(zhàn),那么我就在后邊襲擊大唐。夜間以火,白日以煙為號”