When Should One Kiss the Mezuzah?

Sources: The Rema writes in Yoreh De'ah (Siman 185, Sif 2) that there are those who say that when a person leaves the house and also when a person enters the house, he should place his hand on the mezuzah. However, he did not mention that there is a requirement to kiss the mezuzah or the hand that touched the mezuzah. However, see the Berachot Yosef (there, Ot 4) that according to the opinion of the Ari, zt"l, one should place the finger called the ama on the Shaddai written on the mezuzah and kiss it. In the Teshuvot Shevet HaLevi (Siman 385), it is brought that the custom of the Maharil Diskin, zt"l, was to look at the mezuzah without touching it at all, explaining that he was concerned that it might lead, G-d forbid, to erasure.

When leaving the house, after placing his hand on the mezuzah, he should say: "Hashem will guard my going out and my coming in from now and forever" (Rema there). Some have written to say: "Hashem, who guards me, Hashem, who shields me at my right hand, Hashem will guard my going out and my coming in from now and forever" (Kitzur Shulchan Aruch, Siman 11, Sif 24). And when going on a journey outside the city, he should place his hands on the mezuzot and say: In Your Name, may I go in peace (Shakh, Siman 185, Sif 4, from the Maharil).

There is a story about Maran the Chatam Sofer, zt"l, who examined a young man to determine his fitness for ordination as a rabbi. The young man showed his abilities in Torah, Talmud, and poskim, and was worthy of ordination. The Chatam Sofer had already set his eyes on the young man but was concerned that he might be among the Maskilim. When the young man left his study hall without placing his hand on the mezuzah, the Chatam Sofer decided not to ordain him, as he saw this as a disregard for the customs of our sages and a lack of reverence for heaven (P'Tachai She'arim, Halachot Mezuzah, page 119).

Blessings,

Hillel Meirs