Nature is the primal stuff (pradhāna), the state of balance of the qualities sattva, rajas and tamas. By the qualities of that Nature, its modifications in the form of effect and instrument, actions, worldly and scriptural, are performed in every way. But one whose self is deluded by the sense of I, the sense of I being the notion of self in the aggregate of effect and instrument, the man whose inner instrument is in manifold ways deluded by it, who bears the character of effect and instrument and identifies with them, through ignorance imagining the actions to be in the Self, thinks 'I am the doer of these various actions'. But he who is a knower.

Toward actions being done by the qualities of matter, sattva and the rest, each in its own way, the man whose self is deluded by egotism thinks 'I am the doer'. He whose self is deluded by egotism is one whose self is deluded by egotism: egotism is the conceit of an 'I' toward matter, which is not the 'I'; deluded by it, he, not knowing the true nature of the self, thinks 'I am the doer' in regard to the actions of the qualities. This is the meaning.

This is a brief sub-gloss. For a fuller reading of this verse, see Madhusūdana, Śaṅkara, or Rāmānuja above.

Krishna states the difference in action between the man of knowledge and the ignorant, with 'of nature'. 'By the gunas of nature' means by the senses and the rest. With respect to nature, those are subordinate and bound up with it. For a reflection has no action of its own.