Bhagavad Gita
13.9

इन्द्रियार्थेषु वैराग्यमनहङ्कार एव च । जन्ममृत्युजराव्याधिदुःखदोषानुदर्शनम् ॥

indriyārtheṣu vairāgyamanāhaṅkāra eva ca | janmamṛtyujarāvyādhiduḥkhadoṣānudarśanam ||

Translation

Dispassion toward sense objects, absence of ego, seeing the evil of birth, death, old age, disease, and suffering —

Interpretation

The second set of qualities for true knowledge: indriyartheshu vairagya (dispassion toward sense objects — not hatred of them, but freedom from compulsive attraction), anahankaraha (absence of ego-sense), and then a very specific contemplative practice: janma-mrityu-jara-vyadhi-duhkha-dosha-anudarshana — 'seeing the defect/evil of birth, death, old age, disease, and suffering.' This is the practice of mortality contemplation: regularly meditating on the facts of human suffering to keep the mind from becoming naively comfortable in the body and to maintain spiritual urgency.