Bhagavad Gita · Chapter 3: The Path of Action
Bhagavad Gita 3.26
न बुद्धिभेदं जनयेदज्ञानां कर्मसङ्गिनाम् ।
जोषयेत्सर्वकर्माणि विद्वान् युक्तः समाचरन् ॥
na buddhibhedaṃ janayedajñānāṃ karmasaṅginām | joṣayetsarvakarmāṇi vidvān yuktaḥ samācaran ||
The wise should not unsettle the minds of the ignorant who are attached to action. Acting with discipline themselves, they should encourage others in all their work.
Modern context
A piece of teaching wisdom: do not unsettle people who are working sincerely, even if their motives are mixed. Telling someone that their efforts are 'only ego' usually leaves them with neither their old motivation nor a new understanding. It is better to encourage good work and show a higher way of doing it by one's own example.