יַדְבֵּ֧ק יְהוָ֛ה בְּךָ֖ אֶת־הַדָּ֑בֶר עַ֚ד כַּלֹּת֣וֹ אֹֽתְךָ֔ מֵעַל֙ הָֽאֲדָמָ֔ה אֲשֶׁר־אַתָּ֥ה בָא־שָׁ֖מָּה לְרִשְׁתָּֽהּ׃
גאָט װעט באַהעפֿטן אָן דיר די פּעסט, ביז ער װעט דיך פֿאַרלענדן פֿון דער ערד װאָס דו גײסט אַהין, זי צו אַרבן.
Mishnah Ta'anit
And so too a city which has a plague or [its buildings] collapse that city fasts and they sound a blast, but those [in the places] around it fast but do not sound the alarm. Rabbi Akiva says: they sound the alarm but do not fast. What constitutes a plague? If in a city that can supply five hundred foot-soldiers and three deaths occurred on three consecutive days, behold this constitutes a plague, less than this is not a plague.