כְּבָר בֵּאַרְנוּ שֶׁכָּל יַד הַכֵּלִים שֶׁהַכְּלִי צָרִיךְ לָהּ בִּשְׁעַת תַּשְׁמִישׁוֹ הֲרֵי הִיא חֲשׁוּבָה כְּגוּף הַכְּלִי לְהִתְטַמֵּא וּלְטַמֵּא. לְפִיכָךְ הַטּוֹפֵל כְּלִי חֶרֶס הַבָּרִיא אִם נִטְמָא הַכְּלִי הֲרֵי אוֹכְלִין וּמַשְׁקִין הַנּוֹגְעִין בַּטְּפֵלָה טְהוֹרִין שֶׁאֵין הַכְּלִי צָרִיךְ לִטְפֵלָה זוֹ. אֲבָל הַטּוֹפֵל אֶת כְּלִי חֶרֶס הָרָעוּעַ הֲרֵי הַטְּפֵלָה חֲשׁוּבָה כְּגוּף הַכְּלִי. וְכֵן הַמְהַדֵּק אֶת הַקֵּרוּיָה שֶׁל חֶרֶס הַדּוֹלִין בָּהּ הַמַּיִם אִם חִפָּה אוֹתָהּ בְּעוֹר אוֹ בִּקְלָף וְכַיּוֹצֵא בָּהֶן אִם הָיְתָה רְעוּעָה הֲרֵי הֵן כְּגוּפָהּ:
We already explained that every accessory that is required by an implement when it is being used is considered as an integral element of the implement with regard to both contracting and imparting impurity. Therefore, when one coats an earthenware container which is intact and strong, if the container contracts impurity and foods and/or liquids touch the coating, they are pure. The rationale is that the container does not require this coating. If, however, one coats an unsound earthenware container, the coating is considered as an integral element of the container. Similarly, when one reinforces an earthenware jug used to draw water by covering it with leather, parchment, or the like, if the jug was unsound, the coating is considered as an integral element of the container.
