ם – Mem

Mem מם for Mezuzah (מזוזה)
Mezuzah is a parchment scroll placed in a container that is affixed to the right doorpost of a house. The parchment contains two passages from the Torah:

Hear, O Israel, the L-rd is our G‑d, the L-rd is One.
Love the L-rd your G-d with all your heart and with all your soul
with all your heart and with all your soul,
and with all your strength.
These words, which I am commanding you today,
shall be on your heart. And you shall repeat them diligently to your sons
and speak of them when you sit in your house,
when you walk on the road, when you lie down, and when you get up.
You shall also tie them as a sign to your hand,
and they shall be as frontlets on your forehead.
You shall also write them on the doorposts of your house and on your gates.

A Mezuzah is meant to protect the home and remind its inhabitants of divine commandments. Each person entering the house should touch the Mezuzah or kiss their fingers that touched it.

• What would you write in a message placed at the entrance of your home?
• When guests come to your home, what customs do they follow? What is the first thing they do when they cross the threshold?

Symbolism:
The Hebrew letter ם (Mem) corresponds to the number 40.
Symbolic meaning: water, chaos.