《春秋》記「鄭伯克段于鄢」，《左傳》敘事說理，為之作解。《左傳》敘事與說理部分都存在多種解讀的可能性。《左傳》直解經義，明言「譏失教也」。其意與《毛序》相合。綜合《毛詩》〈將仲子〉及兩〈叔于田〉三篇小序所言，莊公之罪在於未能親愛母弟，為避嫌遠譏，不忍心割斷私恩，任由他多行不義之事，待其作亂然後致討。漢人對此大多了然於心，故楊震、何敞等皆據此勸諫漢帝，不應順從婦人欲求，以免失教之譏。依「失教」之義通讀《左傳》，怡然理順，了無窒礙之處。服虔將「謂之鄭志」連下讀，以為莊公一開始便有殺弟之意，蓄意誘使其弟作反，養成其惡而殺之。其說與《穀梁傳》相通。相較而言，「養惡」之罪大，而「失教」之罪小。自宋以降，論者或主「失教」，或主「養惡」，或二說混合，而「養惡」說尤為世人所主。明代的余邵魚編寫《列國志傳》，旨在依據《左傳》推衍《春秋》褒貶大義，以正人心。就鄭伯克段故事而言，《列國志傳》的敘事結構，一依《左傳》，而情節、人物對話以至議論則與《左傳》頗有出入。余氏改寫《左傳》，敘事多有紕謬、說理亦甚可議，但大路椎輪之功，不可泯也。它為經學通俗化邁出了重要的一步。如說余邵魚將經學融入文學還處於草創階段，作品還十分粗糙，則馮夢龍之作無疑是後出轉精。自中唐《春秋》新學始，學者提倡捨傳求經，直接探尋經文的意旨。宋儒胡安國奉《春秋》為聖人經世之作，於是為《春秋》立新傳。胡氏解說鄭伯克段故事，主要是用誅心之法。其忖度鄭伯心計，絲絲入扣。馮夢龍對胡安國之《春秋》學既有繼承也有推衍。馮氏主張以義斷事，於《左傳》所記，多有取捨。其《新列國志》對《左傳》的簡略處，都能依據一貫的敘事觀點，詳加推衍，使故事變得完整。《新列國志》重點摹寫莊公蓄意養成弟惡，巧妙地將胡《傳》之意融入故事的情節及對話中，使經典與通俗演義融通、經義與教化渾然為一，成為以小說形式敷演經義的成功範例

According to the Chunqiu 春秋, Lord Zhuang of Zheng 鄭莊公 overcame (ke 克) his younger brother Duan 段. In the Zuozhuan 左傳, the narrator not only recounts the causes and consequences of this incident, but also directly judges the characters by elucidating the specific words used in the Chunqiu as well as the comments of the noble man. The central concern of the discussion is with fraternal ties and filial piety. The commentator criticizes Lord Zhuang's failure to fulfill his fraternal role to properly instruct his brother, but praises his efforts to reconcile with his mother, Lady Jiang 姜氏. The reticent narrative invites elaboration and more serious reflection on the accountability of Lord Zhuang. Following the Guliang's 穀梁 comment on this incident, the Han exegete Fu Qian 服虔condemned Lord Zhuang for committing premeditated fratricide, a position echoed by many later interpreters. The incident became established as a historical subject and it appeared in various literary genres, particularly historical fiction. The oldest extant fictional work that discusses the Guliang's judgment is Yu Shaoyu's 余邵 魚 Lieguo zhizhuan (Chronicles of the States 列國志傳). Yu used the historical novel format to reproduce a more detailed story focusing on the power struggle between Lord Zhuang and Duan. This pioneering work differed considerably from the original canonical text. Yu's work was continued by Feng Menglong 馮夢龍, who extensively revised the story and produced the Xin Lieguozhi 新列國志. This latest revision excelled in fictionalizing history by adding dramatic elements and by enriching the plot's development. In addition, Feng's comments on the way that Lord Zhuang treated Duan apparently resonated with those put forth by Fu Qian. More importantly, the historical novel embodied Confucian ideas that were closely related to Feng's scholarly works. This article concludes that the two novelists clearly regarded historical fiction as didactic and as the most efficacious means of upholding, promoting and transmitting Confucian values to the public. As such, their novels have surely played an important role in facilitating the popularization of Confucianism