The following is the results of your search for door-posts.
Door-posts: The Jews were commanded to write the divine name on the posts
(mezuzoth') of their doors
(Deuteronomy 6:9) The Jews, misunderstanding this
injunction, adopted the custom of writing on a slip of parchment
these verses
(Deuteronomy 6:4-9; Deuteronomy 11:13-21) which they enclosed in a reed
or cylinder and fixed on the right-hand door-post of every room in
the house.