労ろうを惜おしまず

expression

sparing no effort; taking pains to do

A set phrase meaning to do something without begrudging the effort, often used in formal or written contexts to describe diligent, painstaking work.

• 彼かれは労ろうを惜おしまず、毎まい日にち遅おそくまで研けん究きゅうを続つづけた。

  He spared no effort and continued his research late every day.

• 労ろうを惜おしまずに準じゅん備びしたおかげで、発はっ表ぴょうは大だい成せい功こうだった。

  Thanks to the painstaking preparation, the presentation was a great success.