Mishnah Parah 10:3: A kallal [a type of stone or earthenware vessel] of chatat [containing the ashes of a red heifer], which touched a [dead] sheretz [certain types of small creature which are impure when dead], is [still] pure. If it [the kallal] was placed on top [of the sheretz], R Eliezer considers them [the ashes] pure, and the Sages consider them impure. If it touched foods or drinks or holy texts, it is pure. If it was placed on top of them, Rabbi Yose considers it pure, and the Sages consider it impure.

קָלָל שֶׁל חַטָּאת שֶׁנָּגַע בְּשֶׁרֶץ, טָהוֹר. נְתָנוֹ עַל גַּבָּיו, רַבִּי אֱלִיעֶזֶר מְטַהֵר, וַחֲכָמִים מְטַמְּאִים. נָגַע בְּאֳכָלִים וּמַשְׁקִין וּבְכִתְבֵי הַקֹּדֶשׁ, טָהוֹר. נְתָנוֹ עַל גַּבֵּיהֶן, רַבִּי יוֹסֵי מְטַהֵר, וַחֲכָמִים מְטַמְּאִים:

Mishnah Parah 10:4: One who is pure for chatat, who [then] touched an oven, with his hand, he is impure, with his foot, he is [still] pure. If he was standing on top of an oven and his hand was outstretched beyond the oven and [holding] in it the jug [with the ashes], and similarly a rod [for holding jugs] placed on top of an oven with two kallalot [hanging] on it, one on one side and one the other, Rabbi Akiva considers them pure, and the Sages consider them impure.

הַטָּהוֹר לְחַטָּאת שֶׁנָּגַע בְּתַנּוּר, בְּיָדוֹ, טָמֵא. וּבְרַגְלוֹ, טָהוֹר. הָיָה עוֹמֵד עַל גַּבֵּי תַנּוּר וּפָשַׁט יָדוֹ חוּץ לַתַּנּוּר, וְהַלָּגִין בְּתוֹכוֹ, וְכֵן הָאֵסֶל שֶׁהוּא נָתוּן עַל גַּבֵּי הַתַּנּוּר וּבוֹ שְׁנֵי קְלָלוֹת, אֶחָד מִכָּאן וְאֶחָד מִכָּאן, רַבִּי עֲקִיבָא מְטַהֵר, וַחֲכָמִים מְטַמְּאִין: