Mahabharata 3.33.16

यत्स्वयं कर्मणा किंचित्फलमाप्नोति पूरुषःप्रत्यक्षं चक्षुषा दृष्टं तत्पौरुषमिति स्मृतम्

yatsvayaṃ karmaṇā kiṃcitphalamāpnoti pūruṣaḥpratyakṣaṃ cakṣuṣā dṛṣṭaṃ tatpauruṣamiti smṛtam

Our plain-language meaning of this verse is waiting for scholar review.