Where does “ob” come from?

ob (Middle High German) comes from Proto-Germanic jabai, from Proto-Indo-European ē- — then, at that time.

Ancestry of “ob”, step by step

StepLanguageWordMeaning
1Proto-Germanicjabaiwhen, if
2Proto-Indo-Europeanē-then, at that time
Every word from Proto-Indo-European ē- →Every word from Proto-Germanic jabai →