Where does “をとつひ” come from?

をとつひ (Old Japanese) comes from Old Japanese 日, from Proto-Japonic *pi — day, sun.

Ancestry of “をとつひ”, step by step

をとつひ traces back through two separate lines of ancestry.

via Old Japanese

StepLanguageWordMeaning
1Old Japanesethe sun; sunlight, sunshine; daytime, daylight
2Proto-Japonic*piday, sun

via Old Japanese

StepLanguageWordMeaning
1Old Japanese
Every word from Proto-Japonic *piEvery word from Old Japanese
をとつひ — Etymology, Origin & Word History | Etymology Explorer