Bhagavad Gita 3.20
कर्मणैव हि संसिद्धिमास्थिता जनकादयः। लोकसंग्रहमेवापि सम्पश्यन्कर्तुमर्हसि।।3.20।।
karmaṇaiva hi saṃsiddhimāsthitā janakādayaḥ| lokasaṃgrahamevāpi sampaśyankartumarhasi||3.20||
karmanaiva hi samsiddhimasthita janakadayah lokasamgrahamevapi sampashyankartumarhasi3.20
Meaning
Even King Janaka and other wise rulers attained perfection through selfless action. You too should act for the welfare of the world, setting an example for others to follow.
जनकादि (ज्ञानी जन) भी कर्म द्वारा ही संसिद्धि को प्राप्त हुए लोक संग्रह (लोक रक्षण) को भी देखते हुए; तुम कर्म करने योग्य हो।
This is verse 20 of 43 in Chapter 3 (Karma Yoga) of the Bhagavad Gita.