Where does “知る由もない” come from?

知る由もない (Japanese) comes from Japanese も, from Old Japanese も, from Proto-Japonic mə, from Arabic مَن — who?; who.

知る由もない (Japanese): to have no way of knowing; to be completely ignorant of

Definitions

  1. to have no way of knowing; to be completely ignorant of

Ancestry of “知る由もない”, step by step

知る由もない traces back through 3 separate lines of ancestry.

via Japanese

StepLanguageWordMeaning
1JapaneseUsed to form the conjectural form of verbs,...
2Old Japanesenon-unique topic marker: also, even
3Proto-Japonicnon-unique topic marker: also, even, too, as well
4Arabicمَنwho?; who

via Japanese 知る

StepLanguageWordMeaning
1Japanese知るto know, be aware of; to learn, acquire; to be...
2Old Japaneseしる
3Proto-Japonicsiruto know

via Japanese ない

StepLanguageWordMeaning
1Japaneseないhaving that quality, having that state; very much...
2Old Japaneseない
Every word from Arabic مَنEvery word from Proto-Japonic Every word from Old Japanese