כָּל שֶׁאַתָּה יָכוֹל לְרַבּוֹת סְפֵקוֹת וּסְפֵקֵי סְפֵקוֹת בִּרְשׁוּת הָרַבִּים טָהוֹר, בִּרְשׁוּת הַיָּחִיד טָמֵא. כֵּיצַד. נִכְנַס לְמָבוֹי וְהַטֻּמְאָה בְּחָצֵר סָפֵק נִכְנַס לֶחָצֵר סָפֵק לֹא נִכְנַס. טֻמְאָה בַּבַּיִת סָפֵק נִכְנַס לַבַּיִת סָפֵק לֹא נִכְנַס. וַאֲפִלּוּ נִכְנַס סָפֵק שֶׁלֹּא הָיְתָה שָׁם סָפֵק הָיְתָה שָׁם. וְאִם תֹּאמַר הָיְתָה שָׁם בְּעֵת שֶׁנִּכְנַס סָפֵק יֵשׁ בָּהּ כְּשִׁעוּר סָפֵק אֵין בָּהּ. וְאִם תֹּאמַר יֵשׁ בָּהּ סָפֵק שֶׁהִיא טֻמְאָה סָפֵק אֵינָהּ טֻמְאָה. וַאֲפִלּוּ הִיא טֻמְאָה סָפֵק נָגַע סָפֵק לֹא נָגַע. סְפֵקוֹ טָמֵא שֶׁהַמָּבוֹי רְשׁוּת הַיָּחִיד:
No matter to what degree doubts and compounded doubts are multiplied in a public domain, the person or object involved is pure. In a private domain, by contrast, he is impure. What is implied? If one entered an alley and there was impurity in the courtyard to which the alley led. If there was a question whether or not he entered the courtyard, he is impure because of the doubt, because an alley is considered a private domain. This same ruling applies if: a) there is impurity in a house and there is a doubt whether one entered the house or not, or b) even if one entered, but there was a doubt whether there was impurity there or not, or c) even if one would say that impurity was present when one entered, there is a doubt whether it comprises the required measure or not, or d) even if the substance certainly comprises the required measure, there is a doubt whether it is impure or not, or e) even if it is certainly impure, there is a doubt whether or not one touched it.
