Bhagavad Gita 18.10
न द्वेष्ट्यकुशलं कर्म कुशले नानुश्ज्जते |
श्रद्धा सत्त्वसमाविष्टो मेधावी छिन्नसंशय:
Translation
Those who neither avoid disagreeable work nor seek work because it is agreeable are persons of true renunciation. They are endowed with the quality of the mode of goodness and have no doubts (about the nature of work).