“Wise people, after they have listened to the laws, become serene, like a deep, smooth, and still lake.”
The still-lake image links serenity with disciplined understanding: calm is portrayed not as blankness but as a settled mind shaped by hearing and absorbing the teaching.
Source details
Dhammapada 82, F. Max Müller translation, Project Gutenberg #2017. The verse belongs to a Buddhist canonical collection and remains a textual source voice rather than a quotation by a modern individual author.