Bhagavad Gita 4.19

4.19 He whose undertakings are all devoid of desires and (selfish) purposes and whose actions have been burnt by the fire of knowledge, him the wise call a sage.

One is understood to be in full knowledge whose every endeavor is devoid of desire for sense gratification. He is said by sages to be a worker for whom the reactions of work have been burned up by the fire of perfect knowledge.