Bhagavad Gita · 3.22

न मे पार्थास्ति कर्तव्यं त्रिषु लोकेषु किञ्चन।नानवाप्तमवाप्तव्यं वर्त एव च कर्मणि॥

na me pārthāsti kartavyaṁ triṣhu lokeṣhu kiñchana nānavāptam avāptavyaṁ varta eva cha karmaṇi

O Partha, there is nothing in the three worlds that I need to do, nor is there anything unattained that I need to attain. Yet I continue to engage in action.

— Bhagavad Gita 3.22

Source: Sacred-Texts.com (Sanskrit) + Bhagavad-Gita.io (translations)