expression
make hay while the sun shines; strike while the iron is hot
Proverb meaning one should not miss a good opportunity; equivalent to English 'make hay while the sun shines' or 'strike while the iron is hot'.
好機逸すべからず、今すぐ行動しよう。
Make hay while the sun shines; let's act now.
A classical Japanese expression combining 好機 (good opportunity), 逸す (to miss, classical form of 逸する), and べからず (must not, archaic negative imperative).