Yad Yad Acharati Shreshthahयद्यदाचरति श्रेष्ठः

Bhagavad Gita 3.21 teaches a devotional principle from Krishna’s dialogue with Arjuna.

Bhagavad Gita 3.21
यद्यदाचरति श्रेष्ठस्तत्तदेवेतरो जनः । स यत्प्रमाणं कुरुते लोकस्तदनुवर्तते ॥
भावार्थ
श्रेष्ठ व्यक्ति जैसा आचरण करता है, दूसरे लोग भी वैसा ही करते हैं। वह जिस मानक को स्थापित करता है, संसार उसका अनुसरण करता है।
Meaning
Whatever an excellent person does, others follow. People follow the standard that person sets.

Source: Bhagavad Gita 3 Sanskrit checked against SanskritDocuments: https://www.sanskritdocuments.org/doc_giitaa/bhagvadnew.html ; meanings checked against IIT Kanpur Gita Supersite and Vedabase chapter 3: https://www.gitasupersite.iitk.ac.in/srimad?field_chapter_value=3&field_nsutra_value=21&language=dv ; https://vedabase.io/en/library/bg/3/