(20) MISHNAH (the earliest code of rabbinic law): For the proclamation of six New Moon days, messengers are sent out: for Nissan, on account of the Passover; for Ab, on account of the fast (ninth of Ab); for Elul, on account of New Year's; for Tishri, in order to arrange the dates of the [remaining] festivals; for Kislev, on account of Chanukah (the Feast of Maccabees); for Adar, on account of the Feast of Purim (the Feast of Esther). (21) GEMARA (the rabbinic commentary on the Mishnah): Why were they not also sent out for Tamuz and Tebheth [for the fasts]? (Ib. b) Did not R. Ghana b. Bizna say, in the name of R. Simon, the pious: "What is the meaning of the passage (Zach. 8, 19) Thus saith the Lord of hosts; the fast of the fourth, and the fast of the fifth, and the fast of the seventh, and the fast of the tenth shall become in the house of Judah joy and gladness, etc.; i.e., they are called fasts, and also days of joy and gladness! We must therefore say that in peaceful times they shall be for joy and gladness, but, when there is no peace, they shall be fasts." [Hence they were always observed] "This is the meaning," said R. Papa, "when there is peace, these days should be for joy and gladness; in the time of persecution they shall be fasts; at times when there are neither persecutions nor peace, people may or may not fast, as they see fit." If that is so, why then [should messengers have been sent out] on account of the fast of Ab (during peaceful times)? "The fast [ninth day] of Ab is different," explained R. Papa, "since many misfortunes occurred on that day; as the master said: 'On the ninth of Ab, the first and second Temples were destroyed, Bether was captured, and the city of Jerusalem was razed to the ground.' "