《隋书·列传·卷二十八》
炀帝慰劳他说： 你是国家的大臣，使我无西顾之忧。 
帝劳之曰： 社稷之臣也。使朕无西顾之忧。 
Emperor Yang praised him and said, “You are a great minister of the country. You have allowed me not to worry about the situation to the west.”