In the concluding portion of the Book Numbers, Moses chronicles the forty-two journeys that the Israelites traveled in the desert—while en route from Egypt to the Promised Land. For the most part the list is very concise – "They traveled from X and camped in Y; they traveled from Y and camped in Z..." – omitting the events that transpired in the areas where they camped. For example, the Sinai Desert stopover is mentioned without reference to the giving of the Torah that occurred there. There are, however, several exceptions, where the list is interrupted to point out an event that occurred at a particular location. One of these exceptions is the encampment at Mount Hor:

"They journeyed from Kadesh and camped at Mount Hor, at the edge of the land of Edom. Aaron the High Priest ascended Mount Hor at G‑d's behest and died there, on the first day of the fifth month, in the fortieth year of the Children of Israel's exodus from Egypt"—Numbers 33:38.

Interestingly, this is the only time that the Torah mentions the exact date of a yahrtzeitInterestingly, this is the only time that the Torah mentions the exact date of a yahrtzeit (anniversary of death). Also interesting is the fact that the section containing this yahrtzeit is always read within a week of the yahrtzeit—the first day (Rosh Chodesh) of Av. And some years, when Rosh Chodesh Av is on Shabbat, we read about Aaron's yahrtzeit on the very date when it is observed!

This begs the obvious question: what is so remarkable about the timing of Aaron's yahrtzeit that it merits explicit mention in the Torah?

Aaron's passing is also associated with another event. While the Israelites traveled through the desert they were ensconced and protected by Clouds of Glory from all sides. This special miracle was in the merit of Aaron's righteousness. With Aaron's passing, these clouds departed, leaving the Israelites vulnerable to the elements and to enemy strikes. And indeed, the King of Arad immediately took advantage of this development, and mounted an attack.

On a deeper level:

Aaron was the ultimate peacemaker. Our Sages tell us that he was a "lover and pursuer of peace," who always sought to bring peace between rivals and quarreling spouses. His efforts were rewarded in kind, with the appearance of Clouds of Glory that served as a unifying force, molding the entire Israelite encampment into a cohesive unit. And as long as the Israelites were united they were insulated against their enemies—for we are only vulnerable to outside attacks when discord reigns in our midst. When Aaron passed away, leaving the nation bereft of his peacemaking efforts, the clouds disappeared. There was a resulting lack of unity, and the enemy pounced.

The clouds did reappear for a short period (in Moses' merit), but soon after they disappeared for good. Ultimately unity must come from within, stemming from a genuine respect for our fellows, not due to external influences such as a peacemaker or isolationism. Drawing on Aaron's inspiration we must strive to make love for our fellows part and parcel of our character, one that does not depend on external factors.

We have never been more "out of the clouds" than todayAaron passed away on the day that ushers in the saddest month on the Jewish calendar, the month when both Holy Temples were destroyed.

"Why was the first Temple destroyed? Because of three sins—idolatry, sexual indiscretions and murder. The second Temple – when the people were involved in Torah, mitzvot and acts of kindness – why was it destroyed? Because they harbored baseless hatred towards each other!"—The Talmud.

In order to rectify our lack unity, we were dispatched on an exile which took us to all corners of the globe. We have never been more "out of the clouds" than today. Spread out all over and divided into different communities, affiliations and ancestries, our biggest challenge is to remain united despite all the differences in ethnicities, customs, ideologies, etc.

We have left the cloud, and now we must internalize Aaron's message of love and peace. This will immunize us against our enemies' designs, and will hasten the day when we will all be returned to our land with joy, and these mournful days will be celebrates as festive holidays.