pō / shuǐ / nán / shōu / zuò / jué / dìng / yǐ / qián / yí / dìng / yào / kǎo / lǜ / qīng / chǔ

泼水难收，做决定以前一定要考虑清楚。

What is done cannot be undone, so you must think carefully before making a decision.