Bhagavad Gita · 2.56

दुःखेष्वनुद्विग्नमनाः सुखेषु विगतस्पृहः।वीतरागभयक्रोधः स्थितधीर्मुनिरुच्यते॥

duḥkheṣhv anudvigna-manāḥ sukheṣhu vigata-spṛhaḥ vīta-rāga-bhaya-krodhaḥ sthita-dhīr munir uchyate

One whose mind is not disturbed by sorrow, who has no longing for pleasure, and who is free from attachment, fear, and anger — such a sage is called one of steady wisdom.

— Bhagavad Gita 2.56

Source: Sacred-Texts.com (Sanskrit) + Bhagavad-Gita.io (translations)