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 日

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

via Old Japanese つ

StepLanguageWordMeaning
1Old Japaneseつ—
Every word from Proto-Japonic *pi →Every word from Old Japanese 日 →