What is the spiritual meaning of Tisha B’Av? What is the significance of the three

weeks between the 17th of the month of Tamuz and the Ninth of Av, and why have those dates been burned into the collective consciousness of the people of Israel? How come every major calamity—from the shattering of the tablets by Moses, to the destruction of the first and second temples, and the Spanish expulsion—took place on the ninth of Av or during the 3 weeks that precede it called “Between the straits”? Is it just a coincidence or part of a bigger plan?