Srimad-Bhagavatam: Canto 11 - Chapter 1 - Verse 10

Sanskrit:

स्वधर्मस्थो यजन् यज्ञैरनाशी:काम उद्धव ।न याति स्वर्गनरकौ यद्यन्यन्न समाचरेत् ॥ १० ॥

ITRANS:

sva-dharma-stho yajan yajñairanāśīḥ-kāma uddhavana yāti svarga-narakauyady anyan na samācaret

Translation:

My dear Uddhava, a person who is situated in his prescribed duty, properly worshiping by Vedic sacrifices but not desiring the fruitive result of such worship, will not go to the heavenly planets; similarly, by not performing forbidden activities he will not go to hell.

Purport:

The perfection of karma-yoga is described here. One who does not desire fruitive rewards for his religious activities does not waste time going to the heavenly planets for celestial sense gratification. Similarly, one who does not neglect his prescribed duty or perform forbidden activities will not be bothered by going to hell for punishment. Thus avoiding material rewards and punishments, such a desireless person can be promoted to the platform of pure devotional service to Lord Kṛṣṇa.