Where does “swerien” come from?

swerien (Old High German) comes from Proto-West Germanic swarjan, from Proto-Germanic swarjaną, from Proto-Indo-European swēr- — heavy.

Ancestry of “swerien”, step by step

StepLanguageWordMeaning
1Proto-West Germanicswarjanto swear
2Proto-Germanicswarjanąto swear
3Proto-Indo-Europeanswēr-heavy
Every word from Proto-Indo-European swēr- →Every word from Proto-Germanic swarjaną →Every word from Proto-West Germanic swarjan →