10הוֹאִיל וְהַיָּדַיִם שְׁנִיּוֹת אִם נָגְעוּ בְּמַשְׁקֶה עֲשָׂאוּם תְּחִלָּה. וְאִם נָגְעוּ מַשְׁקִין אֵלּוּ בָּאֳכָלִין עוֹשִׂין אוֹתָן שֵׁנִי. וְאִם נָגְעוּ בְּמַשְׁקִין אֲחֵרִים עוֹשִׂין אוֹתָן תְּחִלָּה שֶׁהַמַּשְׁקִין תְּחִלָּה לְעוֹלָם כְּמוֹ שֶׁבֵּאַרְנוּ. אֲבָל אֵין מַשְׁקִין אֵלּוּ שֶׁנִּטְמְאוּ מֵחֲמַת הַיָּדַיִם מְטַמְּאִין כֵּלִים שֶׁעִקַּר טֻמְאַת הַיָּדַיִם מִדִּבְרֵיהֶם. וְכֵן גָּזְרוּ חֲכָמִים עַל כָּל אָדָם שֶׁיֹּאכַל אֳכָלִין טְמֵאִין בֵּין שֶׁאָכַל אֹכֶל רִאשׁוֹן אוֹ אֹכֶל שֵׁנִי וְעַל כָּל הַשּׁוֹתֶה מַשְׁקִין טְמֵאִים שֶׁיִּהְיֶה שֵׁנִי לְטֻמְאָה עַד שֶׁיִּטְבּל. וְאִם נָגַע בָּאֳכָלִין עֲשָׂאָן שְׁלִישִׁי. וְאִם נָגַע בְּמַשְׁקִין אֲפִלּוּ מַשְׁקֶה חֻלִּין עֲשָׂאָן תְּחִלָּה לְטַמֵּא אֳכָלִין וּמַשְׁקִין אֲחֵרִים. אֲבָל לֹא לְטַמֵּא כֵּלִים הוֹאִיל וְעִקַּר טֻמְאַת אָדָם זֶה מִדִּבְרֵיהֶם. וּמִפְּנֵי מָה גָּזְרוּ טֻמְאָה עַל הָאוֹכֵל אֳכָלִין טְמֵאִים. שֶׁמָּא יֹאכַל אֹכֶל רִאשׁוֹן אוֹ שֵׁנִי וְיִשְׁתֶּה עָלָיו מַשְׁקֶה תְּרוּמָה וְנִמְצָא הַמַּשְׁקֶה תְּרוּמָה טָמֵא בָּאֹכֶל שֶׁבְּפִיו. וְכֵן הַשּׁוֹתֶה מַשְׁקִין טְמֵאִים שֶׁמָּא יֹאכַל עִמָּהֶן אֹכֶל תְּרוּמָה וְנִמְצָא טָמֵא בְּמַשְׁקִין שֶׁבְּפִיו. וּכְבָר בֵּאַרְנוּ בִּתְרוּמוֹת שֶׁאָסוּר לֶאֱכל תְּרוּמָה טְמֵאָה:
Since a person's hands are considered second degree derivatives of impurity, if they touch liquids, they cause them to be considered as primary derivatives. If such liquids touch foods, they cause them to be considered as secondary derivatives. If such liquids touch other liquids, they cause them to be considered as primary derivatives, for liquids are always considered as primary derivatives, as we explained. Such liquids that contracted impurity due to contact with hands do not impart impurity to keilim, for the fundamental impurity of the hands is of Rabbinic origin. Similarly, our Sages decreed that any person who partook of impure foods - whether the foods were primary or secondary derivatives of impurity - or who drank impure liquids should be considered as a secondary derivative of impurity until he immerses in a mikveh. If he touches foods, he causes them to be considered as a tertiary derivative. If he touches liquids, even ordinary liquids, he causes them to be considered as a primary derivative and they impart impurity to other foods and liquids. They do not impart impurity to keilim, because the impurity contracted by this person is fundamentally a Rabbinic decree. Why was it decreed that a person who partakes of impure foods contracts impurity? For perhaps he will partake of food that is a primary or secondary derivative of impurity and, at the same time, drink a liquid that is terumah. The liquid that is terumah will contract impurity from the food in his mouth. Similarly, if a person is drinking impure liquids, there was concern that he might eat food that is terumah with them and impart impurity to it because of the liquids in his mouth. We have already explained in Hilchot Terumah that it is forbidden to partake of impure terumah.