かっしても盗泉 とうせん みず まず
ka' shitemo tōsenno mizuo nomazu

Expression

1. better starve than fatten on ill-gotten wealth; don't lower yourself to unjust acts, no matter how desperate you are; refraining to drink from a spring called Robber's Spring even if thirsty — literal

Proverb
かっしても盗泉 とうせん みず まず。
kasshitemo nusume izumino mizuwa no. mazu
The eagle does not catch flies.