The Biblical Significance of the Month of Av
Av is the fifth month of the Hebrew calendar, and it is considered the most tragic month in Jewish history. On the Ninth of Av, both the First and the Second Temple in Jerusalem were destroyed. Jewish tradition adds that also on that day, the ten spies brought the evil report about the land, saying they would not be able to conquer it.
Tisha be-av, or the 9th of Av, is the most significant date in the month of Av and it marks the culmination of three weeks of mourning which started in the previous month on 17th Tammuz. 9th of Av is a fast day, the book of Lamentations is read in the synagogues, and the nation reflects on the causes of these tragedies.
The Biblical record describing the destruction of the First Temple by Nebuchadnezzar is found in Jeremiah 52:12-14.