Reference for Kelim 6:3
שָׁלֹשׁ אֲבָנִים שֶׁעֲשָׂאָן שְׁתֵּי כִירַיִם, נִטְמֵאת אַחַת מִן הַחִיצוֹנָה, הָאֶמְצָעִית הַמְשַׁמֶּשֶׁת אֶת הַטְּמֵאָה, טְמֵאָה. הַמְשַׁמֶּשֶׁת הַטְּהוֹרָה, טְהוֹרָה. נִטְּלָה הַטְּהוֹרָה, הֻחְלְטָה הָאֶמְצָעִית לְטֻמְאָה. נִטְּלָה הַטְּמֵאָה, הֻחְלְטָה הָאֶמְצָעִית לִטְהוֹרָה. נִטְמְאוּ שְׁתַּיִם הַחִיצוֹנוֹת, אִם הָיְתָה הָאֶמְצָעִית גְּדוֹלָה, נוֹתֵן לָזוֹ כְדֵי שְׁפִיתָה מִכָּאן וְלָזוֹ כְדֵי שְׁפִיתָה מִכָּאן, וְהַשְּׁאָר טָהוֹר. וְאִם הָיְתָה קְטַנָּה, הַכֹּל טָמֵא. נִטְּלָה הָאֶמְצָעִית, אִם יָכוֹל לִשְׁפֹּת עָלֶיהָ יוֹרָה גְדוֹלָה, טְמֵאָה. הֶחֱזִירָהּ, טְהוֹרָה. מֵרְחָהּ בְּטִיט, מְקַבֶּלֶת טֻמְאָה מִשֶּׁיַּסִּיקֶנָּה כְּדֵי לְבַשֵּׁל עָלֶיהָ אֶת הַבֵּיצָה:
Three stones on which two ovens are made: if one of the outer ones became impure, the half of the middle one that serves the impure one is impure, but the [half of it] that serves the pure one remains pure. If he removed the pure one, the middle one is completely transferred to the impure one. If he removed the impure one, the middle one is completely transferred to the pure one. If the two outer ones become impure, if the middle stone was large, one outer stone is assigned a part of it that suffices for the support of a pot and the other outer stone a part of it that suffices for the support of a pot, and the remainder is pure. But if it was small, all of it is impure. If he removes the middle stone, if he can set a big pot on it [the stove], they [the outer stones] are impure. If he put it back, they all are pure. If he plastered it [the middle stone] with clay, it becomes susceptible to impurity when it is heated to a degree that suffices for the cooking of an egg.