The Children of Israel began building the "Mishkan" (also called the "Tabernacle"--a portable sanctuary to house the Divine presence in their midst as they journeyed through the desert) on the 11th of Tishrei of the year 2449 from creation (1312 BCE) -- six months after their Exodus from Egypt, four months after the revelation at Sinai, and 80 days after their worship of the Golden Calf. The construction of the Mishkan, which followed a detailed set of instructions issued to Moses on Mount Sinai, lasted 74 days, and was completed on the 25th of Kislev; but the Divine command to erect the edifice came only three months later, on the 23rd of Adar, when Moses was instructed to begin a 7-day "training period."
During the week of Adar 23-29, the Mishkan was erected each morning and dismantled each evening; Moses served as the High Priest and initiated Aaron and his four sons into the priesthood. Then, on the "eighth day" -- the 1st of Nissan -- the Mishkan was "permanently" assembled (that is, put up to stand until the Divine command would come to journey on), Aaron and his sons assumed the priesthood, and the divine presence came to dwell in the Mishkan.
Links:
Parshah Terumah (detailed description of Mishkan with commentary)
Why It's Frustrating Having a Brain
More on the Mishkan
Chassidic Rabbi Yitzchak Meir Altar (1799-1866), author of Chiddushei Harim (a commentary on the Talmud and Shulchan Aruch), was a disciple of the Maggid of Koshnitz and Rabbi Simcha Bunim of Peshischa, and the founder of the "Ger" (Gerer) Chassidic dynasty. All his 13 sons had died in his lifetime, and he was succeeded (in 1870) by his young grandson, Rabbi Yehudah Leib Alter (the "Sefat Emmet").
On 18 Adar (March 1) a terrorist opened machine-gun fire on a van filled with Chabad yeshiva students as it began to cross the Brooklyn Bridge from Manhattan, critically wounding two young men and injuring two others. The killer had wished to fire at the Lubavitcher Rebbe—Rabbi Menachem M. Schneerson, of righteous memory—but could not get close enough.
While three wounded students—including one who had a bullet lodged in his brain —recovered, 16-year-old Ari Halberstam succumbed to his wounds five days later on 23 Adar.
It all began with an unbounded light
that filled all and left no room for a world to be.
Then that light was withheld
so that the world might be created in the resulting void.
Then the world was created,
with the purpose of returning to that original state of light
—yet to remain a world.
That is something greater than unbounded light:
A dark world that shines, through our hard work.