Mishnayos Taanis Perek 1 Mishnah 6

If these three regular fasts have passed and they have not been answered with rain, the court decrees three other fasts upon the community. These are severe fasts, in which one may eat and drink only while it is still day, before the beginning of the night of the fast, and on the day of the fast itself they are prohibited to engage in the performance of work, in bathing, in smearing with oil, in wearing shoes, and in marital relations; and they lock the bathhouses so that no one should come to bathe on that day. If these three fasts have passed and they still have not been answered, the court decrees on them another seven fasts, which are a total of thirteen fasts, upon the community, not including the first three fasts observed by individuals. These seven fast days are more severe than the first ones, as on these days, in addition to all the earlier stringencies, they sound the alarm, as will be explained in the Gemara, and they lock the stores. Although shops must remained closed most of the time on these days, on Monday they open them a little at nightfall to allow people to purchase food for breaking their fast, and on Thursday they are permitted to open the stores all day in deference to Shabbat, so that people may purchase food for the sacred day.

עָבְרוּ אֵלּוּ וְלֹא נַעֲנוּ, בֵּית דִּין גּוֹזְרִין שָׁלשׁ תַּעֲנִיּוֹת אֲחֵרוֹת עַל הַצִּבּוּר. אוֹכְלִין וְשׁוֹתִין מִבְּעוֹד יוֹם, וַאֲסוּרִין בִּמְלָאכָה וּבִרְחִיצָה וּבְסִיכָה וּבִנְעִילַת הַסַּנְדָּל וּבְתַשְׁמִישׁ הַמִּטָּה, וְנוֹעֲלִין אֶת הַמֶּרְחֲצָאוֹת. עָבְרוּ אֵלּוּ וְלֹא נַעֲנוּ, בֵּית דִּין גּוֹזְרִין עֲלֵיהֶם עוֹד שֶׁבַע, שֶׁהֵן שְׁלשׁ עֶשְׂרֵה תַּעֲנִיּוֹת עַל הַצִּבּוּר. הֲרֵי אֵלּוּ יְתֵרוֹת עַל הָרִאשׁוֹנוֹת, שֶׁבָּאֵלּוּ מַתְרִיעִין וְנוֹעֲלִין אֶת הַחֲנוּיוֹת, בַּשֵּׁנִי מַטִּין עִם חֲשֵׁכָה, וּבַחֲמִישִׁי מֻתָּרִין מִפְּנֵי כְבוֹד הַשַּׁבָּת: