The Bhagavad Gita (dated between the 2nd century BCE and 2nd century CE)
“The person whose mind
is free from anxiety
and free from greed
with rage, passion and fear gone,
whose thoughts are firm,
that one is said to be a sage.”
- This quote is from discourse/chapter 2, verse 56 of the Bhagavad Gita (a Hindu scripture included in book 6 of the epic poem, the Mahabharata). The translation used here is by Laurie L. Patton (Penguin Classic, 2014).