Verse
ज्ञानं ज्ञेयं परिज्ञाता त्रिविधा कर्मचोदना ।करणं कर्म कर्तेति त्रिविधः कर्मसंग्रहः ॥
Knowledge, the object of knowledge and the knower, these three things constitute the mental impulsion to work; there are again three things, the doer, the instrument and the work done, that hold the action together and make it possible.
Gītā 18·18