Matthew 23:2

Sit on Moses' seat (epi th Mwusew kaqedra ekaqisan). The gnomic or timeless aorist tense, ekaqisan, not the aorist "for" the perfect. The "seat of Moses" is a brief form for the chair of the professor whose function it is to interpret Moses. "The heirs of Moses' authority by an unbroken tradition can deliver ex cathedra pronouncements on his teaching" (McNeile).