It is a positive commandment for a person to affix mezuzot on his gates, in order that a person be protected by G-d when he goes out or comes into his house. A second reason for the commandment relating to mezuzot is that a person should never forget G-d, similar to the mitzvah of tzitzit. When a person sees these remembrances, he is reminded to fulfill the commandments of his Master.
In Proverbs, it is written that there are two levels that wait by a person's door. One is the mezuzah, representing the Shechinah , and one is a demon that has permission to cause damage, standing on the left hand side of the door. If a person lifts up his eyes and sees the secret of the name of G-d and remembers Him, the demon is not able to harm him.
When the Jews left Egypt, Moses acceded to take along a "mixed multitude" of non-Jews with them, people who had not been fully educated about the ways of Judaism and the path of the Torah. G-d did not want to accept these unfit converts. Had they not joined the Jewish people, there would have been no death or exile.
But Moses accepted them, thinking that it would be good to absorb them into holiness, harnessing their unrefined power for holy purposes. However, this "mixed multitude" made errors in judgment throughout Israel's trek in the desert, often drawing the Jewish people into their errors as well. Moses' trans-generational job is to rectify their impurity until it is fully matured.
Moses had not consulted G-d regarding the acceptance of the Mixed Multitude. In addition he had developed a personal interest in the conduct of these people and was anxious to convert them. Alas, not only did Moses fail to truly convert them but they also infected the Israelites proper with their lack of faith during the episode of the Golden Calf.
These people and their offspring by now made up the majority of the Jews in the desert. Moses was forced to insert an extra year (the Jubilee year) after every 49 years to serve as a warning that Israel must not again err by accepting converts wholesale and being misled by them.
On Shabbat we are commanded to refrain from doing forbidden labors and to sanctify it by making Kiddush on wine, using clean clothes and fresh bedding, eating good food etc. The essence of the day is to elevate even the physical aspects of Shabbat to become spiritual.
"Now, Israel"….
The name "Israel" represents the lofty aspect of the victor in battle. It is used specifically "now", during exile, in terms of the victory of the G-dly soul over the animal soul. In the World to Come, when physical reality reveals its true G-dly source and this battle will no longer be necessary, the Jewish people will no longer be referred to by this name.
Exile can be compared to pregnancy. Just as during pregnancy the discomfort grows, so too the pain of the exile grows from minute to minute; Just as the birth of a child is anticipated, so too do we look forward to the end of the exile which will herald a millennium of revelation.
As long as a Jew is performing the commandments with all of his strength, he is already in a state of redemption. He is being guided by the Almighty and all of the obstacles to holiness will fall away. May all the days of the month of Av be transformed to days of joy and happiness forever.
"I give in. We’ll go to the Premishlan Rebbe for Shabbos Nachamu," he promised his wife.
Shabbat Shalom.