מקואות ו׳Mikvaot 6

Mishnah 1א׳

כָּל הַמְעֹרָב לַמִּקְוֶה, כַּמִּקְוֶה. חוֹרֵי הַמְּעָרָה וְסִדְקֵי הַמְּעָרָה, מַטְבִּיל בָּהֶם כְּמָה שֶׁהֵם. עֻקַּת הַמְּעָרָה, אֵין מַטְבִּילִין בָּהּ אֶלָּא אִם כֵּן הָיְתָה נְקוּבָה כִשְׁפוֹפֶרֶת הַנּוֹד. אָמַר רַבִּי יְהוּדָה, אֵימָתַי, בִּזְמַן שֶׁהִיא מַעֲמֶדֶת עַצְמָהּ. אֲבָל אִם אֵינָהּ מַעֲמֶדֶת עַצְמָהּ, מַטְבִּילִין בָּהּ כְּמָה שֶׁהִיא:

Any [water] mixed into a mikveh [a gathering of water collected by natural means and immersed in for purification] is considered as the mikveh [if it was already a complete mikveh, containing forty se’ah of valid water]. Regarding holes or cracks in a cavern [which houses a mikveh], one may immerse [objects] in them as they are [regardless of how little water they contain, or how small their connection is to the rest of the mikveh]. Regarding a dug out area [of water] in a cavern, one may not immerse in it unless it was pierced [with a hole connecting it to the mikveh waters] the size of the tube of a flask. Rabbi Yehudah said: when does this apply? When it [the barrier separating between the dug out area and the valid mikveh] holds itself up; but if it does not hold itself up, one may immerse in it as it is.

Mishnah 2ב׳

דְּלִי שֶׁהוּא מָלֵא כֵלִים וְהִטְבִּילָן, הֲרֵי אֵלּוּ טְהוֹרִים. וְאִם לֹא טָבַל, אֵין הַמַּיִם מְעֹרָבִין, עַד שֶׁיִּהְיוּ מְעֹרָבִין כִּשְׁפוֹפֶרֶת הַנּוֹד:

Regarding an [impure] bucket which is full of vessels, if one immerses them, they are [all] pure. But if one did not [intend to] immerse [the bucket, i.e. if the bucket was already pure], the waters [in the bucket and those in the mikveh] do not mix [to render the vessels in the bucket pure], unless they were mixed [through an opening] the size of the tube of a flask.