Bhagavad-Gita: Chapter 4, Verse 20

Rudra Vaisnava Sampradaya:

Visnuswami

Sridhara Swami's Commentary

Once one has given up attachment to actions as a means of obtaining rewards as well as giving up the desire for the rewards of actions one becomes tranquil and content without any need for acquisition or accumulation. Such persons although sometimes appearing to be engaged in actions naturally or prescribed, factually do nothing as all their activities are actually inaction. This is Lord Krishnas meaning here.

Brahma Vaisnava Sampradaya:

Madhvacarya

Madhvacarya's Commentary

It is not only by the mere renunciation of the intention for fruits of desire but also it is essential to renounce the affection and intense liking for these fruits in whatever form one is remembering them. This is what Lord Krishna is emphasising here. The nature of spiritual intelligence is being always tranquil and ever content. By acting in this way one assumes the qualities of the eternally equipoised and infinitely independent Supreme Lord.

Sri Vaisnava Sampradaya:

Ramanuja

Ramanuja's Commentary

Whoever has completely given up all desires and attachments to rewards for actions, who is also nitya-trypto or totally content immersed in the atma or soul, whoever is self satisfied never depending on anything from prakriti or material existence. Such a person although seen to be intently performing various prescribed actions, in reality performs inaction meaning no action that has any binding effect. Because although externally such a person might appear as if performing activities but internally that person is actually cultivating spiritual knowledge and meditating on the atma and thus exempt from any binding effect. Lord Krishna gives the spiritual intelligence aspect of actions is next.

Kumara Vaisnava Sampradaya:

Nimbaditya

Kesava Kasmiri's Commentary

Now Lord Krishna speaks about the non-binding effects that the actions of the spiritually intelligent insure. They are without egoism and unattached to the doership of actions. Being completely satisfied by the bliss they experience within their consciousness they maintain their bodily existence by accepting what comes on its own accord. They are no longer affected by the dualities of life such as good and evil.