Mishnah Parah 5:1: One who brings an earthenware vessel for the chatat [to fill with water to be sanctified by the ashes of the red heifer], he immerses himself [first, for purification], and sleeps at the furnace [in order to make sure no impure person touches it once it is completed]. Rabbi Yehuda says: He can even bring it from the house [of the potter] and it is valid, since [the testimony of] everyone believed regarding the chatat [due to the stringency of the matter]. And regarding trumah [a portion separated from grains and fruit grown in Israel and given to a priest, and which must be kept pure], one should open the furnace and take it [to ensure that the vessel stays pure]. Rabbi Shimon says: from the second row [and not from the first row, since someone impure may have already opened the furnace and touched it]. Rabbi Yose says: from the third row.

הַמֵּבִיא כְּלִי חֶרֶס לְחַטָּאת, טוֹבֵל וְלָן עַל הַכִּבְשָׁן. רַבִּי יְהוּדָה אוֹמֵר, אַף מִן הַבַּיִת הוּא מֵבִיא וְכָשֵׁר, שֶׁהַכֹּל נֶאֱמָנִים עַל הַחַטָּאת. וּבַתְּרוּמָה, פּוֹתֵחַ אֶת הַכִּבְשָׁן וְנוֹטֵל. רַבִּי שִׁמְעוֹן אוֹמֵר, מִן הַסֵּדֶר הַשֵּׁנִי. רַבִּי יוֹסֵי אוֹמֵר, מִן הַסֵּדֶר הַשְּׁלִישִׁי:

Mishnah Parah 5:2: One who immerses a vessel for the chatat in water which is not suitable for sanctifying [for the chatat ritual, by mixing it with the ashes], it needs to be dried; in water which is suitable for sanctifying, it does not need to be dried. If [he intends] to add into it water which has already been sanctified, either way, it requires drying.

הַמַּטְבִּיל כְּלִי לְחַטָּאת בְּמַיִם שֶׁאֵינָם רְאוּיִים לְקַדֵּשׁ, צָרִיךְ לְנַגֵּב. בְּמַיִם שֶׁהֵם רְאוּיִים לְקַדֵּשׁ, אֵינוֹ צָרִיךְ לְנַגֵּב. אִם לְהוֹסִיף לְתוֹכוֹ מַיִם מְקֻדָּשִׁין, בֵּין כָּךְ וּבֵין כָּךְ צָרִיךְ לְנַגֵּב: