“There has been an inversion in the hierarchy of the two principles of antiquity, “Take care of yourself” and “Know yourself.” In Greco-Roman culture, knowledge of oneself appeared as the consequence of the care of the self. In the modern world, knowledge of oneself constitutes the fundamental principle.”

1850s, Judge For Yourselves! 1851 (1876)

The First Octavo Notebook https://docs.google.com/document/d/1gD981HZ190BUJF-3czZNX3DsFWvqp3cq-Z4QS4d-9gw/edit?hl=en
The Blue Octavo Notebooks (1954)

Quoted on his official website (30 December 2008) http://www.plumvillage.org/

Source: Your True Home: The Everyday Wisdom of Thich Nhat Hanh: 365 days of practical, powerful teachings from the beloved Zen teacher

Shah,Sanjay. " “Nikita Ghokale on the Board of Asian School of Fashion And Design” http://blogs.rediff.com/asiannewsagency/2016/11/28/nikita-ghokale-on-the-board-of-asian-school-of-fashion-and-design/.Rediff.com. November 28, 2016.

Knowing Yourself: The True in the False (1996)

Hagakure (c. 1716)
Context: There is a saying of the elders' that goes, "Step from under the eaves and you're a dead man. Leave the gate and the enemy is waiting." This is not a matter of being careful. It is to consider oneself as dead beforehand.

Abide as the Self