73. Come and see, We learned that a fast is good for averting a BAD dream as fire for consuming flax, THAT IS, FOR GETTING RID OF IT. The fast is valuable only on the same day and not in any other day. The reason is that every day below has another supernal day ruling over it. We learned that when one is fasting to avert a dream, the decree is annulled before the day is over. If he postpones it to another day, then it is under the jurisdiction of another day, and no day intermingles with its neighbor day. Similarly, there is a supernal day above appointed over every day, and one should be careful not to damage any day, so that it will not remain defective in relation to other days.
73. ת"ח תָּנֵינָן יָפָה תַּעֲנִית לַחֲלוֹם, כְּאֵשׁ לַנְּעוֹרֶת. וְעִקָּרָא דְּתַעֲנִיתָא בְּהַהוּא יוֹמָא מַמָּשׁ, וְלָאו בְּיוֹמָא אָחֳרָא. מַאי טַעֲמָא. בְּגִין דְּלֵית לְךָ יוֹם לְתַתָּא, דְּלָא שַׁלְטָא בֵּיהּ יוֹמָא אָחֳרָא עִלָּאָה. וְכַד אִיהוּ שָׁארִי בְּתַעֲנִיתָא דְּחֶלְמָא, אוֹלִיפְנָא דְּהַהוּא יוֹמָא לָא אִתְעָדֵי, עַד דְּאִתְבְּטַל הַהוּא גְּזֵרָה. וְאִי דָּחֵי לֵיהּ לְיוֹמָא אָחֳרָא, הָא שׁוּלְטָנָא דְּיוֹמָא אָחֳרָא הוּא, וְלָא עָאל יוֹמָא בְּיוֹמָא אָחֳרָא דְּחַבְרֵיהּ. כְּהַאי גַּוְונָא, לֵית לָךְ יוֹם דְּלָא אִתְמָנָא עָלֵיהּ יוֹמָא עִלָּאָה לְעֵילָּא. וּבָעֵי בַּר נָשׁ לְאִסְתַּמְּרָא, דְּלָא יַעְבִּיד פְּגִימוּ בְּהַהוּא יוֹמָא, וְלָא יִתְפְּגִים קַמֵּי שְׁאָר יוֹמִין אָחֳרָנִין.