Bhagavad Gita · Karma YogaChapter 3, Shloka 20 (3.20)

The example of Janaka. King Janaka is traditionally regarded as a wise royal sage — who remained established in the knowledge of Brahman even while ruling a kingdom (he is mentioned in the Upanishads and in stories of the Mahabharata).

Shankaracharya — two possibilities. (1) If Janaka and the others had attained samyag-darśana (complete knowledge), then, because of prārabdha-karma (the momentum of actions already set going), they attained perfection while acting without taking up renunciation, for the sake of loka-saṅgraha. (2) If they had not attained complete knowledge, they attained perfection gradually through action and sattva-śuddhi. And for Arjuna: if you think that action is not necessary for the wise, tathāpi — even so, prārabdha-karmāyattaḥ — you (as a kshatriya) are subject to actions already set going, and with an eye to the welfare of the world you should act.

Acharya Ramanuja — even the foremost of the wise through karma-yoga. Janakādayo rājarṣayo jñāninām agresarāḥ karma-yogena eva saṃsiddhim āsthitāḥ ātmānaṃ prāptavantaḥ — Janaka and the other royal sages, foremost among the wise, attained the self through karma-yoga itself. Ramanuja also shows the sequence of the section here: first it was said that karma-yoga is for those not fit for jnana-yoga; then that karma-yoga is better even for one fit for jnana-yoga; now it is said that a śiṣṭa (a person regarded as an exemplar) must in any case practise karma-yoga alone.