成王和唐叔虞平时闲居，拿一个梧桐叶当做玉珪，交给唐叔虞说:“我用这个封你。”叔虞高兴地把这件事告诉了周公，周公因此向成王请示说:“天子要封虞吗?”成王说:“只是我自己和唐叔虞开玩笑罢了。”周公说:“我听说，天子不说玩笑话。天子说的话，史官要记载，乐工要歌诵，士要颂扬。”于是就封唐叔虞在晋地。周公旦可以说是善于言辞的了，一发言使得成王更重视说话，表明了爱抚弟弟的意思，又辅佐了王室。 英语 nto Wang Hetang uncle danger stays at ordinary times, take a sycamore leaves as stating, jade to shu yu of tang said: \"I use this letter you.\" Uncle danger delighted to tell it to the duke of zhou, zhou therefore to the king asking said: \"son of heaven to seal danger?\" And the king said: \"just kidding myself and tang suyu.\" Duke said: \"I hear that, son of heaven does not speak a joke. Right, the official to record, to the harvest, and to celebrate.\" Hence sealing shu yu of tang in jin. Duke of zhou is soft-spoken, attach more importance to speak a speech made into king, show the meaning of love brother, and for the royal family.