I got my quote slightly wrong so I this time I cut and pasted it from Mindfully.org translated by Stephen Mitchell.
Fill your bowl to the brim
and it will spill.
Keep sharpening your knife
and it will blunt.
Chase after money and security
and your heart will never unclench.
Care about people's approval
and you will be their prisoner.
Do your work, then step back.
The only path to serenity.