No, it’s not a Jewish doorbell. It's a home security device called a mezuzah, and it’s wired into the Ultimate Protection Agency.

The software inside this gadget is a scroll with the words beginning, “Hear O Israel, the L‑rd is our G‑d; the L‑rd is one.” Those powerful words sum up the mandate of a Jew: to infuse the world with G‑d’s oneness. We place the mezuzah on our doorposts, and G‑d’s oneness surrounds us and protects us.

You’ll need:

  1. A mezuzah scroll. The mezuzah must be hand-written by a scribe, on specially prepared parchment, with specific types of quill and ink. The market is filled with printed or improperly prepared mezuzahs, so make sure to purchase yours from a reliable source.
  2. We place them on our doorposts, and G‑d’s oneness surrounds us and protects usA protective case.
  3. Hammer and nails, strong glue or double-sided tape.

Where:

On every doorway in your home or office leading into a proper room—a space at least 6.5 × 6.5 feet—except for the bathroom. This includes hallways, walk-in closets, etc.

On the right doorpost—going with the direction towards which the door opens. If the door leads into a house, affix it to the right of a person entering, even if the door swings outwards. In a doorless doorway, think about importance and function, and place to the right of the entry to the more important room.

At the bottom of the top third of the doorpost, on a diagonal, with the top pointing inwards.

How:

Recite:

Blessed are you, L‑rd our G‑d, King of the universe, who has sanctified us with His commandments and commanded us to affix a mezuzah.

Affix the mezuzah(s). One blessing suffices for all the mezuzahs affixed in one uninterrupted session.

Touch the mezuzah as you enter and leave, and then kiss the fingers that touched it.

At least twice in seven years, have your mezuzahs professionally checked, to ascertain that they are intact and that no letters have been cracked or erased.