Mishnah Parah 10:1: Anything capable of becoming impure due to midras [a type of impurity due to being sat on by certain types of impure individuals, which can then transfer impurity to other things] is madaf [treated as if ritually impure due to midras] for chatat, [regardless of] whether it is impure or pure. [This is all part of an extra stringency imposed by the rabbis to elevate the purity of the chatat.] And people are also like this [like objects capable of becoming ritually impure due to midras, they too become madaf for chatat]. Things which are capable of becoming impure due to contact with a corpse, [regardless of] whether they are pure or not, Rabbi Eliezer says: "they are not madaf." Rabbi Yehoshua says: "they are madaf." And the Sages say: "one that is impure is madaf, one that is pure is not madaf."

כֹּל הָרָאוּי לִטַּמֵּא מִדְרָס, מַדָּף לְחַטָּאת, בֵּין טָמֵא בֵּין טָהוֹר. וְאָדָם, כַּיּוֹצֵא בוֹ. כֹּל הָרָאוּי לִטַּמֵּא טְמֵא מֵת, בֵּין טָמֵא בֵּין טָהוֹר, רַבִּי אֱלִיעֶזֶר אוֹמֵר, אֵינוֹ מַדָּף. רַבִּי יְהוֹשֻׁעַ אוֹמֵר, מַדָּף. וַחֲכָמִים אוֹמְרִים, הַטָּמֵא, מַדָּף. וְהַטָּהוֹר, אֵינוֹ מַדָּף:

Mishnah Parah 10:2: One who is pure for chatat, who [then] touched a madaf object, is made impure [for chatat]. Jugs [which are sufficiently pure and intended for holding the waters] for a chatat, which [then] touched a madaf object, are made impure [for chatat]. One who is pure for chatat, who [then] touched foods or drinks, if [he touched them] with his hand, he is impure, if with his foot, he his pure. If he moved them with his hand [without touching them], Rabbi Yehoshua considers him impure, and the Sages consider him pure.

הַטָּהוֹר לְחַטָּאת שֶׁנָּגַע בְּמַדָּף, טָמֵא. לָגִין שֶׁל חַטָּאת שֶׁנָּגַע בְּמַדָּף, טָמֵא. הַטָּהוֹר לְחַטָּאת שֶׁנָּגַע בְּאֳכָלִים וּמַשְׁקִים, בְּיָדוֹ, טָמֵא. וּבְרַגְלוֹ, טָהוֹר. הֱסִיטָן בְּיָדוֹ, רַבִּי יְהוֹשֻׁעַ מְטַמֵּא, וַחֲכָמִים מְטַהֲרִים: