北宋中后期，洛阳聚集了一批以司马光、二程为代表的士大夫学者。程颢、程颐兄弟讲学于此，以“天理”为核心重新解释儒家经典；他们的言论由门人记录，后编为《河南程氏遗书》，成为宋明理学的重要源头。
In the middle and late Northern Song, Luoyang gathered a circle of scholar-officials led by Sima Guang and the two Cheng brothers. Cheng Hao and Cheng Yi taught there, reinterpreting the Confucian classics around the idea of “heavenly principle”; their sayings were recorded by their disciples and later compiled as the Surviving Writings of the Cheng Family of Henan, one of the wellsprings of Song–Ming Neo-Confucianism.
杨时，字中立，福建将乐人；游酢，字定夫，福建建阳人。二人同出程颢门下，与吕大临、谢良佐并称“程门四先生”。
Yang Shi, courtesy name Zhongli, was from Jiangle in Fujian; You Zuo, courtesy name Dingfu, was from Jianyang in Fujian. Both had studied under Cheng Hao, and together with Lü Dalin and Xie Liangzuo they were known as the Four Masters of the Cheng school.
元祐年间，程颢已经去世。杨时、游酢都已年过四十，各有官职与文名，却仍以弟子之礼北上洛阳，再拜程颐为师。
By the Yuanyou era Cheng Hao had died. Yang Shi and You Zuo were both past forty, each with an official post and a literary reputation, yet they still went north to Luoyang and, with the full courtesy of disciples, took Cheng Yi as their teacher.
据《宋史·杨时传》记载，一天他们登门求见，程颐恰好“瞑坐”——闭目静坐。二人不敢惊动，便“侍立不去”，在旁恭敬等候。
According to the “Biography of Yang Shi” in the History of Song, one day they called at his house and found Cheng Yi “sitting with eyes closed” — deep in quiet meditation. Not daring to disturb him, the two “stood in attendance and did not leave”, waiting respectfully at his side.
等到程颐睁开眼，天色已晚，门外的积雪已深达一尺。一段没有一句对话的等待，就这样成了后世传诵的画面。
When Cheng Yi opened his eyes, the day was far gone and the snow outside the door had piled up a foot deep. A wait in which not a single word was spoken thus became one of the most cherished scenes of later tradition.
程颐感其诚敬，倾囊相授。杨时学成南归，在故乡龟山讲学，世称“龟山先生”，门人弟子遍及东南。
Touched by their reverence, Cheng Yi taught them everything he had. When his studies were complete, Yang Shi returned south and taught at Guishan in his home district, where he was known as “Mr. Guishan”; his students spread across the southeast.
他所承继的二程之学，经罗从彦、李侗传至朱熹，终于汇成影响中国近千年的程朱理学。程颢当年送他南归时那句“吾道南矣”，也被后人看作这一脉学问南传的预言。
The learning of the two Cheng brothers that he carried onward passed through Luo Congyan and Li Tong to Zhu Xi, and at last became the Cheng–Zhu school that shaped China for nearly a thousand years. The words Cheng Hao spoke when he saw Yang Shi off to the south — “my Way has gone south” — were later read as a prophecy of that southward transmission.
“程门立雪”四字并非宋人原话，而是后人对这则轶事的概括。它所推重的，不只是师生之间的礼节，更是一种把学问置于身份、年龄与辛苦之上的态度。
The four characters 程门立雪 were not the Song authors’ own words but a later summary of the anecdote. What they honor is not only the courtesy between teacher and student, but a readiness to put learning above rank, age, and hardship.