Rabbi Shlomo Yitzchaki, known as "Rashi", passed away on the 29th of Tammuz of the year 4865 from creation (1105 CE).
Rashi was born in Troyes, France, in 1040. His commentaries on the Torah,
Prophets and Talmud are universally accepted as the most basic tool for the understanding of these texts for schoolchild and scholar alike. Numerous commentaries have been authored on his commentary. In his famed "Rashi talks", the Lubavitcher Rebbe repeatedly demonstrated how Rashi's "simple meaning of the text" style enfolds many layers of meaning, often resolving profound difficulties in the text and presenting new, innovative interpretations with a simple word choice or rephrasing of a Midrashic passage.
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.