《新唐書》裏有篇《李密傳》，
風趣的故事有一段，
說的是隋末遼東有一人，
名叫李密很能幹。
他年輕時在皇室做侍衛，
辦事情機智又果敢。
想不到隋煬帝說他不老實，
下旨把他的差事免。
李密一點也不懊喪，
回家發奮把書念。
一次李密騎牛出門去，
把一部《漢書》掛在牛角邊，
一邊趕路一邊讀，
被宰相楊素巧遇見。
楊素心中暗稱奇，
坐車慢慢跟後邊，
問清了讀書少年是李密，
走近親切把話談，
看出了李密不是平庸輩，
回家後喚來兒子楊玄感，
告訴他李密的才氣與學識，
要兒子經常去找李密玩。
從那後兩個少年成好友，
砥行礪誌把學問鑽。
到後來覺察隋朝已腐敗，
及時起兵把隋反。
楊玄感拜了李密做軍師，
李密幫他出謀劃策奪江山。
誰想關鍵時玄感未從李密計，
兵敗身亡後果慘。
李密無處把身存，
投靠了瓦崗寨義軍仍造反。
到後來當上一名大首領，
燃得那農民起義火燎原，
沉重地打擊了統治者，
英名代代往後傳。
“牛角掛書”這成語，
比喻人勤奮讀書肯鑽研。
Hang a Book on a Cow's Horn
In the“New History of Tang Dynasty”there was a biography of Li Mi。It was a very interesting story。It said that a man in the last reign of Sui Dynasty（581—618A。D。）in Liaodong Peninsular，by the name of Li Mi who was quite able。As a young man he served as a bodyguard in the court，where he proved to be witty and brave。But unfortunately Emperor Yang of Sui said he was dishonest，and ordered an end to his post。Young Li Mi，however，was not discouraged，and indulged in reading when he was back home。
One day，Li Mi went out of his village on cowback，hanging the“History of Han”on the horn of the cow。He was reading while travelling。It happened the prime minister Yang Su caught sight of this。Yang Su was amazed at the young lad，and followed him slowly in his imperial wagon。He was told that the lad's name was Li Mi，and approached him to talk to him。He found out Li Mi was not a nobody，and hurried home to call up his son Yang Xuangan。He told his son that Li Mi was talented and knowledge-able，and asked his son to frequent his place。