An Etymological Dictionary of the German Language/Annotated/Strähle
Strähle, feminine, ‘comb,’ from the equivalent Middle High German strœl, masculine, to which Modern High German and Middle High German strœlen, ‘to comb,’ is allied; the equivalent Old High German verb strâlen (*strâllen, *stralian) presumes also for Old High German a substantive strâl, meaning ‘comb.’ It is not improbable that the separate teeth of the comb were regarded as arrows, rays.