That would be slokha or stanza from Chanakya an ancient Indian sage
In the original sanskrit it would read like….
मनसा चिन्तितं कार्यं वाचा नैव प्रकाशयेत्। मन्त्रेण रक्षयेद् गूढं कार्य चापि नियोजयेत् ॥
The english pronunciations would roughly come as
Manasa chintitam kaaryam vacha naiv prakashayet
Mantreyn rakshayed goodham kaarye chaApi niyojayet
And the all important meaning is …
Whatever the mind has contemplated, should not be expressed from the mouth. Thinking it over, it must be kept a secret and without announcing the thought, it must be implemented in action
Have followed this principle through out my adult life. Do not justify my actions or talk about it to all instead implement it through my actions.