内に省みて疚しからず
Meanings
1
I have nothing to be ashamed of; I have a clean conscience
A classical Chinese-derived expression from the Analects of Confucius. Used to assert that one's heart is clear after honest self-reflection. Literary and somewhat formal; not everyday speech.
The phrase 'Uchi ni kaerimite yamashikarazu' comes from the Analects of Confucius.
He always strives to live in a way that he can say with his head held high, 'I have nothing to be ashamed of upon self-reflection.'