One idea introduced in this chapter has had a career far beyond it. Krishna points out that he himself has nothing to gain in any of the three worlds and nothing he has not got, and yet he continues to act, because if he did not, people would follow his example and the worlds would fall into ruin. He acts for the holding together of the world.
The word carries an obligation that is easy to miss. It is not addressed to everyone equally; it is addressed to the person whom others watch. What the eminent do, the rest do; the standard they set is the standard followed. An exemplary actor therefore cannot treat their own conduct as a private matter, and cannot withdraw from work on the grounds that they personally no longer need its results. Arjuna is such a person, and this is a direct answer to his proposal to walk away.
The chapter gives the ancient king Janaka as the precedent, a ruler who reached perfection by action rather than by leaving his kingdom for the forest. That example matters in a tradition where renunciation had enormous prestige, because it insists that the householder and the ruler have a road of their own and are not simply doing the second best thing.
The passage closes with a formula the Gita returns to in its final chapter: one's own duty, even imperfectly performed, is better than another's duty performed well, and better to die in one's own than to take up another's, which brings danger. Read as consolation it is generous. Read as social prescription it has been used to argue that people should stay where birth put them, and the two readings have never been fully separated.