Rabbi Aharon Berachia ben Moshe of Modina (? - 1639) was an Italian Kabbalist and a student of Rabbi Menachem Azariah of Fano. At the request of the Burial Society at Mantua, he instituted rites for them. The author of many Kabbalistic works, he is perhaps best known for his work Ma'abar Yabbok, which contains mystical dissertations on purity and holiness. He also wrote additional prayers to be offered for the sick and the dead, as well as a code of conduct for their treatment. Many of the prayers recited at the gravesites of the deceased were composed by him.
Tradition has it that an angel called a "maggid" would come and study with him, similar to the angel that would visit Rabbi Yosef Caro.
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