Teaching
Offer your best effort to the work before you, but do not hand your peace over to the result.
Original Text
Karmany evadhikaras te ma phaleshu kadachana.
Transliteration: Karmany evadhikaras te ma phaleshu kadachana.
Meaning
This teaching does not reject goals. It reminds you that peace comes from right action, while outcomes are shaped by many factors beyond your control.
Practical Application
Before an important task, write down one outcome you want and three actions you control. Commit to the actions, review the learning afterward, and refuse to measure your worth only by the result.
Source
Bhagavad Gita, 2.47
Attributed to: Sri Krishna