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 , and 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.

These dictionary topics are from
M.G. Easton M.A., D.D., Illustrated Bible Dictionary, Third Edition,
published by Thomas Nelson, 1897. Public Domain, copy freely.