Bhagavad Gita Chapter 13, Verse 10

असक्तिरनभिष्वङ्गः पुत्रदारगृहादिषु | नित्यं च समचित्तत्वमिष्टानिष्टोपपत्तिषु ||

asaktir anabhiṣvaṅgaḥ putra-dāra-gṛhādiṣu nityaṁ ca sama-cittatvam iṣṭa-aniṣṭa-upapattiṣu

Non-attachment and absence of clinging to sons, wife, home, and so on, and constant equanimity of mind in desired and undesired occurrences.

Krishna continues listing qualities that lead to understanding. 'Asaktiḥ anabhiṣvaṅgaḥ'—non-attachment and absence of clinging, even to those closest to you—sons, wife, home. This doesn't mean you don't care. It means you're not attached. You can love without clinging. You can care without being consumed. 'Nityaṁ sama-cittatvam'—constant equanimity of mind. 'Iṣṭa-aniṣṭa-upapattiṣu'—in desired and undesired occurrences. When things go your way, you're equanimous. When they don't, you're equanimous. This equanimity creates the stability needed for understanding. When you're attached to relationships, possessions, outcomes, you're stuck in the field. When you're equanimous, you can recognize the knower. The field includes relationships, possessions, outcomes. The knower remains constant regardless of them.