nLev. 11:40 “He also who carries its carcass shall wash his clothes and be unclean until evening.”
nGod told Moses to wash after handling dead things
(~ 1400 BC.)
nUntil the 1800’s doctors handled the dead and then treated patients without washing.
nPhillip
Semmelweiss proved that disease can be transferred by not washing after handling dead things (~ 1846 AD.)