expression
needless to say; it goes without saying
Used to introduce something obvious or universally accepted, often at the beginning of a statement.
断るまでもなく、健康は何よりも大切だ。
Needless to say, health is more important than anything.
断るまでもなく、彼はその仕事を引き受けた。
It goes without saying that he accepted the job.
More common and versatile; 断るまでもなく is slightly more formal and emphasizes that no refusal or objection is needed.
From 断る (to refuse, to decline) + までもなく (even without doing). Literally 'even without refusing', it evolved to mean something so obvious that there is no need to refuse or object.