"and the L–rd will skip over the blood": Now does this not follow a fortiori, viz.: If of the blood (on the door) of the Pesach (Passover) of Egypt, the less "formidable," which obtains only for a circumscribed time, and which did not obtain (both) in the daytime and at night, (but only at night), and which does not obtain for future generations, it is written (Ibid.) "and He will not permit the destroyer, etc.", then (the mitzvah of) mezuzah, the more formidable, containing (in Scripture) ten citations (of the name of the L–rd), and which obtains (both) in the daytime and at night, and which obtains for all generations, how much more so should He not permit the destroyer, etc."! But why is this not the case? Our sins have prevented it. As it is written (Isaiah 59:2) "But your transgressions have separated between you and your G–d, and your sins have hidden His face from you against hearing."