Where does “比を求める” come from?

比を求める (Japanese) comes from Japanese を, from Proto-Japonic wo — accusative marker; away from, off.

Ancestry of “比を求める”, step by step

比を求める traces back through two separate lines of ancestry.

via Japanese を

StepLanguageWordMeaning
1JapaneseをA case particle; A conjunctive particle, usually...
2Proto-Japonicwoaccusative marker; away from, off

via Japanese 比

StepLanguageWordMeaning
1Japanese比the Philippines; ratio; compare to
Every word from Proto-Japonic wo →Every word from Japanese を →