הַנּוֹגֵעַ בְּמֵי חַטָּאת שֶׁלֹּא לְצֹרֶךְ הַזָּאָה בֵּין אָדָם בֵּין כֵּלִים טָמֵא וְאֵינוֹ מְטַמֵּא בְּגָדִים בִּשְׁעַת מַגָּעוֹ. שֶׁנֶּאֱמַר (במדבר יט כא) "וְהַנֹּגֵעַ בְּמֵי הַנִּדָּה יִטְמָא עַד הָעָרֶב". הִנֵּה לָמַדְתָּ שֶׁמֵּי הַנִּדָּה אָב מֵאֲבוֹת הַטֻּמְאוֹת שֶׁל תּוֹרָה. וְטֻמְאַת מַגָּעָן בְּכָל שֶׁהוּא. וְאִם הָיָה בָּהֶן כְּדֵי הַזָּאָה מְטַמְּאִין בְּמַגָּע וּבְמַשָּׂא. וְהַנּוֹגֵעַ בָּהֶן אוֹ שֶׁנּוֹשְׂאָן שֶׁלֹּא לְצֹרֶךְ מְטַמֵּא בְּגָדִים בִּשְׁעַת מַגָּעוֹ אוֹ בִּשְׁעַת מַשָּׂאוֹ עַד שֶׁיִּפְרשׁ מִמְּטַמְּאָיו שֶׁנֶּאֱמַר (במדבר יט כא) "וּמַזֵּה מֵי הַנִּדָּה יְכַבֵּס בְּגָדָיו". אֵינוֹ מְדַבֵּר בְּמַזֶּה עַל הַטָּמֵא אִם טִהֵר אֶת הַטָּמֵא קַל וָחֹמֶר שֶׁיִּהְיֶה הוּא טָהוֹר. מִפִּי הַשְּׁמוּעָה לָמְדוּ שֶׁזֶּה שֶׁנֶּאֱמַר בַּתּוֹרָה וּמַזֵּה מֵי הַנִּדָּה לֹא נֶאֱמַר אֶלָּא לְשִׁעוּר שֶׁהַנּוֹגֵעַ אוֹ הַנּוֹשֵׂא מֵי נִדָּה שֶׁיֵּשׁ בָּהֶן כְּדֵי הַזָּיָה שֶׁלֹּא לְצֹרֶךְ הַזָּאָה טָמֵא וּמְטַמֵּא בְּגָדִים דִּין תּוֹרָה. וְכַמָּה הוּא שִׁעוּר הַזָּאָה כְּדֵי שֶׁיִּטְבּל רָאשֵׁי גִּבְעוֹלִין שֶׁל אֵזוֹב בְּמַיִם. בַּמֶּה דְּבָרִים אֲמוּרִים שֶׁמֵּי חַטָּאת מְטַמְּאִין בִּזְמַן שֶׁנָּגַע בָּהֶן אוֹ נְשָׂאָן שֶׁלֹּא לְצֹרֶךְ קֹדֶם שֶׁיַּעֲשׂוּ מִצְוָתָן. אֲבָל אַחַר שֶׁעָשׂוּ מִצְוָתָן אֵינָן מְטַמְּאִין כְּלָל. כֵּיצַד. הֲרֵי שֶׁטָּבַל אֶת הָאֵזוֹב וְהִזָּה עַל הָאָדָם הַטָּמֵא אוֹ עַל הַכֵּלִים וְהָיוּ הַמַּיִם שׁוֹתְתִין וְיוֹרְדִין מֵעַל הַטָּמֵא לָאָרֶץ. וְכֵן הַמַּיִם הַנִּתָּזִין בִּשְׁעַת הַזָּאָה עַל הָאָרֶץ אוֹ עַל הַטָּהוֹר הֲרֵי אוֹתָן הַמַּיִם טְהוֹרִים וְהַנּוֹגֵעַ בָּהֶן וְהַנּוֹשְׂאָן טָהוֹר. הִטְבִּיל אֶת הָאֵזוֹב לְהַזּוֹת עַל דָּבָר שֶׁאֵינוֹ מְקַבֵּל טֻמְאָה הֲרֵי הַמַּיִם הַמְנַטְּפִין כְּשֵׁרִין לְהַזּוֹת מֵהֶן כְּמוֹ שֶׁבֵּאַרְנוּ. לְפִיכָךְ מְטַמְּאִין טֻמְאַת מֵי חַטָּאת לְפִי שֶׁלֹּא עָשׂוּ מִצְוָתָן שֶׁהֲרֵי הַטְּבִילָה הָיְתָה לְשֵׁם דָּבָר שֶׁאֵינוֹ מְקַבֵּל טֻמְאָה:
Any person or article which touches sanctified water for a purpose other than sprinkling contracts impurity. The person does not impart impurity to his clothes, however, even when touching the water, as Numbers 19:21 states: "One who touches the sprinkling water will become impure until the evening." Thus it is derived that the sprinkling water is a primary source of impurity according to Scriptural Law and even the slightest amount of it imparts ritual impurity. If there is enough water to sprinkle, it imparts impurity when touched and when carried and one who touches it or carries it for a purpose other than sprinkling imparts impurity to his clothes when touching it or carrying it until he separates himself from the source of his impurity, as implied by ibid. which states: "One who sprinkles the water shall launder his garments." Now this is not speaking about someone who sprinkles water on an impure person, for if he purifies an impure person, one can certainly infer that he himself remains pure. According to the Oral Tradition, it was taught that the Torah's statement "One who sprinkles the water shall launder his garments" was stated only to teach the measure that imparts impurity; i.e., that if one touches or carries a measure of sanctified water that could be sprinkled for an intent other than sprinkling, he is impure and he imparts impurity to his garments according to Scriptural Law. How much is a measure of sprinkling? Enough to immerse the tops of the stalks of hyssop in the water. When does the statement that the water for this purification imparts impurity apply? When one touched it or carried it for an intent other than sprinkling before they were used for their mitzvah. After they were used for their mitzvah, by contrast, they do not impart impurity at all. What is implied? One immersed the hyssop in the sanctified water and sprinkled it on an impure person or keilim and the water was dripping and descending from the impure person to the ground or when he sprinkled the water, water was sprinkled on the ground or on a pure person, that water is pure and one who touches or carries it is pure. If one immersed the hyssop to sprinkle water on an object that is not susceptible to ritual impurity, the water which drips from it is fit to be sprinkled again, as we explained. Therefore they impart the impurity of sanctified water to one who touches or carries them because they were not used for their mitzvah, for the immersion of the hyssop was for the intent of sprinkling on something that is not susceptible to ritual impurity.
