Bhagavad Gita 2.57

यः सर्वत्राणभिस्नेहस्तत्तत्प्राप्य शुभाशुभम् |
नाभिनन्दति न द्वेष्टि तस्य प्रज्ञा प्रतिष्ठिता

Translation

One who remains unattached under all conditions, and is neither delighted by good fortune nor dejected by tribulation, he is a sage with perfect knowledge.