Bhagavad Gita · 3.21

यद्यदाचरति श्रेष्ठस्तत्तदेवेतरो जनः।स यत्प्रमाणं कुरुते लोकस्तदनुवर्तते॥

yad yad ācharati śhreṣhṭhas tat tad evetaro janaḥ sa yat pramāṇaṁ kurute lokas tad anuvartate

Whatever a great person does, others follow. Whatever standards they set, the world pursues.

— Bhagavad Gita 3.21

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