Rabbi Avraham Chaim Na'eh (1890-1954) was born in Hebron to Rabbi Menachem Mendel Na'eh, a Lubavitcher chassid and dean of the Magen Avot, a yeshiva founded by the S'dei Chemed. With the outbreak of World War One, the Ottomans, who controlled the Land of Israel at the time, expelled anyone who was not a citizen of the empire. Most of the exiled Jews, including Rabbi Avraham Chaim, gathered in Alexandria, Egypt. During his time there, Rabbi Avraham Chaim founded Yeshivat Eretz Yisrael and wrote the halachic work Shenot Chaim, a concise digest of halachah for Sephardic Jews. In 1918, he returned to Palestine to work for the Edah HaChareidit (a prominent Orthodox communal organization), under Rabbi Yosef Chaim Sonnenfeld.
Rabbi Na'eh best known for his halachic works Ketzot ha-Shulchan and Shiurei Torah ("measurements of the Torah"), in which he converted halachic measurements into modern terms. Contemporary halachic authorities follow his measurements to this day.
During the Three Weeks, from 17th of Tamuz to the 9th of Av, we commemorate the conquest of Jerusalem, the destruction of the Holy Temple and the dispersion of the Jewish people.
Weddings and other joyful events are not held during this period; like mourners, we do not cut our hair, and various pleasurable activities are limited or proscribed. (The particular mourning customs vary from community to community, so consult a competent halachic authority for details.)
Citing the verse (Isaiah 1:27) "Zion shall be redeemed with mishpat [Torah] and its returnees with tzedakah," the Rebbe urged that we increase in Torah study (particularly the study of the laws of the Holy Temple) and charity during this period.
Links:
The Three Weeks
There are two sorts of inner convictions of the soul, this thing we call faith.
Unbound by the confines of space and time, your soul sees a reality your mind cannot fathom. From that vision seeps down a conviction that G-d is with you, that He is good, and that there is really nothing else but Him.
Not because you understand. But because your soul sees that this is so. And she sees with a clarity and certainty the flesh eye could never attain.
Nevertheless, a higher vision means there are two and not one: There is you and there is the vision you perceive. And if there are two, two can be separated.
So that, when darkness and confusion swells and storms, threatening to rip you away from your G-d, a higher vision is not enough.
That is when you need to reach to the very core of your soul. Not to that place in the soul that sees G-d, but to the essence of the soul that is truly a part of G-d.
To say, "This is my G‑d. I am His, He is mine, and we are one."
"And so, nothing can stand between us."