"When you teach someone,
both teacher and student benefit"
教学相长
(jiàoxué-xiāngzhǎng)

The idiom 教学相长 (jiào xué xiāng zhǎng) translates to "teaching and learning promote each other." It originates from the Xue Ji (学记), an ancient text in the Liji (礼记, Book of Rites), a classical Confucian work. In this context, the phrase describes the mutually beneficial relationship between teacher and student, where both parties grow through the process of teaching and learning.

The full passage states: "虽有嘉肴，弗食不知其旨也；虽有至道，弗学不知其善也。故学然后知不足，教然后知困。知不足然后能自反也，知困然后能自强也。故曰教学相长也" which translates to "Even if there are delicious dishes, one cannot know their taste without eating them; even if there is a profound way, one cannot know its goodness without learning it. Thus, learning makes one aware of inadequacies, and teaching reveals one's difficulties. Knowing inadequacies leads to self-reflection; knowing difficulties brings self-strengthening. Therefore, it is said: teaching and learning promote each other."

This idea reflects the Confucian emphasis on humility and the continuous pursuit of knowledge. Teaching is not merely about imparting knowledge but a way for teachers to solidify and expand their understanding through the questions and perspectives of their students. Similarly, students contribute to the teacher's growth by challenging them to think in new ways, fostering a dynamic of mutual enrichment.

In contemporary settings, this idiom applies well beyond formal education. It suggests that any role involving guidance—whether in mentorship, coaching, or leadership—benefits from a reciprocal exchange where both parties are enriched. This idiom is often cited to remind teachers, leaders, and mentors that learning is an unending journey, one in which humility and openness to new insights are essential for true growth.