Bhagwad Gita
Chapter 8, Verse 3
श्री भगवानुवाच
अक्षरं ब्रह्म परमं स्वभावोऽध्यात्ममुच्यते।
भूतभावोद्भवकरो विसर्गः कर्मसंज्ञितः।।8.3।।
The Supreme Lord said, The indestructible, transcendental living entity is called Brahman, and his eternal nature is called the self. Action pertaining to the development of these material bodies is called karma, or fruitive activities.