글 속에도 글 있고 말 속에도 말 있다. There is writing within writing as there are words within words.

This proverb reminds the listener that there is infinite meaning hidden within both spoken and written words. It has the double meaning of insisting that some things are best written just as some things are best spoken. The expression would thus be used when this was not the case with someone’s choice of words. (1. 말과 글에 담겨 있는 뜻은 무궁무진함을 비유적으로 이르는 말. 2. 글이라고 하여 다 글이 아니며 말이라고 하여 다 말이 아니라는 뜻으로, 쓸 만한 글과 말은 따로 있음을 비유적으로 이르는 말.)