This greek statement line the one "Know yourself" give a guide for the ethics as a suggestion for a better live, a live in harmony with the world and Being that allows the people who take care of others and of the world to get the knowledge of the Being as a whole thing. An ethic for the battle and for the love, for estetics of nature and arts and enjoy the live in an abundance. To allow you to be as you are in a better growth and expect the death with honour.
Moreover the harmony with the world should be get with the care of important things in the live that allow ys to go far from ourselves and participate in the Being with every action of our lives. To be proud of ourselves as living Being with love and care to the world and others. This is the way how one can get peace to see the future without fear and enjoy the things of live.
As Foucualt writes, romans used to send letters, ever between men, to describe the activities of the day, like collecting grapes, walking by his fields or sleeping in hora sexta. Greeks were more worried about ethics and discussing in agora.