yajñārthāt karmaṇo ‘nyatra
loko ‘yaḿ karma-bandhanaḥ
tad-arthaḿ karma kaunteya
Translation of Bhagavad Gita 3.9
Work done as a sacrifice for Vishnu has to be performed, otherwise work causes bondage in this material world. Therefore, O son of Kunti, perform your prescribed duties for His satisfaction, and in that way you will always remain free from bondage.
Commentary by Sri A.C. Bhaktivedanta Swami Prabhupada of Gaudiya Sampradaya:
Since one has to work even for the simple maintenance of the body, the prescribed duties for a particular social position and quality are so made that that purpose can be fulfilled. Yajna means Lord Vishnu, or sacrificial performances. All sacrificial performances also are meant for the satisfaction of Lord Vishnu. The Vedas enjoin: yajno vai vishnuh. In other words, the same purpose is served whether one performs prescribed yajnas or directly serves Lord Vishnu. Krishna consciousness is therefore performance of yajna as it is prescribed in this verse. The varnashrama institution also aims at satisfying Lord Vishnu. Varnashramacaravata purusena parah puman/ vishnur aradhyate (Vishnu Purana 3.8.8).
Therefore one has to work for the satisfaction of Vishnu. Any other work done in this material world will be a cause of bondage, for both good and evil work have their reactions, and any reaction binds the performer. Therefore, one has to work in Krishna consciousness to satisfy Krishna (or Vishnu); and while performing such activities one is in a liberated stage. This is the great art of doing work, and in the beginning this process requires very expert guidance. One should therefore act very diligently, under the expert guidance of a devotee of Lord Krishna, or under the direct instruction of Lord Krishna Himself (under whom Arjuna had the opportunity to work). Nothing should be performed for sense gratification, but everything should be done for the satisfaction of Krishna. This practice will not only save one from the reaction of work, but also gradually elevate one to transcendental loving service of the Lord, which alone can raise one to the kingdom of God.
Commentary by Sri Vishvanatha Chakravarthi Thakur of Gaudiya Sampradaya:
“The smrti scriptures say that one is bound by actions: karmana badhyate jantuh. (Mahabharata 12.241.7) Therefore, I will become bound by performing actions.”
“No, action offered to the Supreme Lord does not bind one.” That is explained in this verse.
“Dharma offered to Visnu without personal desire is called yajna. Persons become bound by karma by any other actions for any other purpose. Therefore you should perform actions for the perfection of such dharma.”
“But even if I perform actions which are offered to Visnu, if I perform them with desires, then I will still become bound.”
“One should become devoid of the desire for results (mukta sangah).”
Thus the Lord spoke to Uddhava:
sva-dharma-stho yajan yajnair anasih-kama uddhava
na yati svarga-narakau yady anyan na samacaret
asmil loke vartamanah sva-dharma-stho ‘naghah sucih
jnanam visuddham apnoti mad-bhaktim va yadrcchaya
My dear Uddhava, a person who is situated in his prescribed duty, properly worshiping by Vedic sacrifices but not desiring the fruitive result of such worship, will not go to the heavenly planets; similarly, by not performing forbidden activities he will not go to hell.
One who is situated in his prescribed duty, free from sinful activities and cleansed of material contamination, in this very life obtains transcendental knowledge or, by fortune, devotional service unto Me. SB 11.20.10-11