Bhagavad Gita Chapter 4, Verse 13

चातुर्वर्ण्यं मया सृष्टं गुणकर्मविभागशः | तस्य कर्तारमपि मां विद्ध्यकर्तारमव्ययम् ||

cātur-varṇyaṁ mayā sṛṣṭaṁ guṇa-karma-vibhāgaśaḥ tasya kartāram api māṁ viddhy akartāram avyayam

The four-fold social order was created by Me according to division of qualities and action. Though I am its creator, know Me to be the non-doer and imperishable.

Krishna explains that social roles (cātur-varṇyam) are based on guṇa (qualities/natures) and karma (actions), not birth. 'Guṇa-karma-vibhāgaśaḥ' means division according to qualities and actions—people fit different roles based on their nature and work, not family lineage. Then he reveals a paradox: 'Mayā sṛṣṭam' (created by Me) yet 'akartāram avyayam' (non-doer, imperishable). This shows Krishna creates the system but isn't bound by it—he acts without attachment, without being the 'doer' in the ordinary sense. This verse sets up the teaching about action without attachment that follows. It also addresses the question of social order: roles exist based on nature and action, not rigid birth-based hierarchy.