《旧五代史·后周·太祖纪一》
当初，隐帝的军队战败时，太祖对宋延渥说 ：你是皇帝女婿，是皇亲，可赶快去保护皇上，顺便带上奏章，请陛下找机会赶快到我这里来，以免被身边的人谋害。 
初、官军之败，帝谓宋延渥曰： 尔国亲，可速往卫主上，兼附奏，请陛下得便速奔臣军，免为左右所图。 
At first, when Yin Di's army was defeated, Taizu said to Song Yanwo: "You are the emperor's son-in-law and the imperial relative. You can go and protect the emperor quickly. By the way, bring the memorial and ask his majesty to take the opportunity to come to me quickly, so as not to be murdered by the people around him."