Five things happened to our fathers on the Seventeenth of Tammuz and five on the Ninth of Av.

On the Seventeenth of Tammuz: the tablets [of the Ten Commandments] were broken, the daily offering ceased, the city [walls of Jerusalem] were breached, Apostomus burned the Torah and set up an image in the sanctuary.

On the Ninth of Av: it was decreed that our fathers would not enter the Land of Israel, the Temple was destroyed the first and second times, Betar was captured, and the City [of Jerusalem] was plowed up. When Av comes in, we minimize gladness. . . .

In the week in which the Ninth of Av falls, hair-cutting and clothes-washing are prohibited, but they are permitted on Thursday in honor of the Sabbath. On the eve of the Ninth of Av one may not eat two cooked dishes, eat meat, or drink wine. Rabban Simeon ben Gamliel says: "One most simply make some change." Rabbi Judah requires turning over one's bed, but the Sages do not agree with him.