This punishment was not, however, as severe as it might appear, for none among them died below the ages of sixty, whereas those who had at the time of the exodus from Egypt been either below twenty or above sixty were entirely exempt from this punishment. Besides only such were smitten as had followed the counsel of the spies, whereas the others, and the Levites and the women were exempt. Death, moreover, visited the transgressors in such fashion that they were aware it was meant as punishment for their sins.
Throughout all the year not one among them died. On the eighth day of the month of Ab, Moses would have a herald proclaim throughout the camp, "Let each prepare his grave." They dug their graves, and spent there the following night, the same night on which, following the counsel of the spies, they had revolted against God and Moses. In the morning a herald would once more appear and cry: "Let the living separate themselves from the dead."
Those that were still alive arose, but about fifteen thousand of them remained dead in their graves. After forty years, however, when the herald repeated his customary call the ninth day of Ab, all arose, and there was not a single dead man among them. At first they thought they had made a miscalculation in their observation of the moon, that is was not the ninth day of Ab at all, and that this was the reason why their lives had been spared.
Hence they repeated their preparations for death until the fifteenth day of Ab. Then the sight of the full moon convinced them that the ninth day of Ab had gone by, and that their punishment had been done away with. In commemoration of the relief from this punishment, they appointed the fifteenth day of Ab to be a holy day.