Mishnah Parah 5:9: Two stones made to surround one another, forming a trough [between them], and similarly two willows, and similarly a trough which was divided [into two], the water in between them is not sanctified [when the water in the troughs is]. If they were formed with plaster or gypsum and they can be lifted as one [vessel], the water between them is sanctified [along with the water in the troughs].

שְׁתֵּי אֲבָנִים שֶׁהִקִּיפָן זוֹ לָזוֹ וַעֲשָׂאָן שֹׁקֶת, וְכֵן שְׁתֵּי עֲרֵבוֹת, וְכֵן הַשֹּׁקֶת שֶׁנֶּחְלְקָה, הַמַּיִם שֶׁבֵּינֵיהֶם אֵינָן מְקֻדָּשִׁין. עֲשָׂאָן בְּסִיד אוֹ בְגִפְסִים וְהֵן יְכוֹלוֹת לְהִנָּטֵל כְּאַחַת, הַמַּיִם שֶׁבֵּינֵיהֶם מְקֻדָּשִׁין:

Mishnah Parah 6:1: One who is sanctifying [water for the chatat ritual by adding the ashes of the heifer], if the sanctified[ashes] fell on his hand or on the [vessel's] side and afterwards fell onto the trough [and into the water], it is invalid. If it [the ashes] fell from the tube into the trough [on their own], it is invalid. If he took [ashes] from the tube and covered it [the tube] or closed the door [before putting the ashes in the water], the sanctified[ashes he is holding] are valid, and the water is invalid [since he has done other work during the process of sanctifying the water]. If he set it [the tube] upright into the ground [before mixing in the ashes], [the sanctification] is invalid [since he has done other work in between]; If [he set it upright] in his hand it is valid, because it is (im)possible [otherwise].

הַמְקַדֵּשׁ וְנָפַל הַקִּדּוּשׁ עַל יָדוֹ אוֹ עַל הַצַּד וְאַחַר כָּךְ נָפַל עַל הַשֹּׁקֶת, פָּסוּל. נָפַל מִן הַשְּׁפוֹפֶרֶת לַשֹּׁקֶת, פָּסוּל. נָטַל מִשְּׁפוֹפֶרֶת וְכִסָּה, אוֹ שֶׁהֵגִיף אֶת הַדֶּלֶת, הַקִּדּוּשׁ כָּשֵׁר, וְהַמַּיִם פְּסוּלִים. זְקָפָהּ בָּאָרֶץ, פָּסוּל. לְתוֹךְ יָדוֹ, כָּשֵׁר, מִפְּנֵי שֶׁאֶפְשָׁר: