《新唐书·列传·卷一百四十六》
皇帝派使者责备，同时召伏允入朝。伏允称病不入朝而为儿子求婚，用以窥测皇帝的心思。
帝遣使者让，且召伏允；以疾为解，而为子求婚，验帝意。
The Emperor sent envoys to reprimand him and at the same time summoned Fu Yun to the imperial court. Fu Yun claimed illness to avoid appearing at court and asked for marriage with the emperor's son, in order to test the emperor's intentions.