"lay" as in "layman" or "lay preacher" does have the derivation you give. As a verb, "lay it down" has Germanic roots, e.g. "liegen". The Greek cognate seems t

"lay" as in "layman" or "lay preacher" does have the derivation you give. As a verb, "lay it down" has Germanic roots, e.g. "liegen". The Greek cognate seems to be "lexos", "bed". (All this from Skeat's etymological dictionary.)