Talmud for Parah 12:2
הִזָּה, סָפֵק מִן הַחוּט, סָפֵק מִן הַכּוּשׁ, סָפֵק מִן הַגִּבְעוֹל, הַזָּיָתוֹ פְסוּלָה. הִזָּה עַל שְׁנֵי כֵלִים, סָפֵק עַל שְׁנֵיהֶם הִזָּה, סָפֵק מֵחֲבֵרוֹ מִצָּה עָלָיו, הַזָּיָתוֹ פְסוּלָה. מַחַט שֶׁהִיא נְתוּנָה עַל הַחֶרֶס, וְהִזָּה עָלֶיהָ, סָפֵק עַל הַמַּחַט הִזָּה, סָפֵק מִן הַחֶרֶס מִצָּה עָלֶיהָ, הַזָּיָתוֹ פְסוּלָה. צְלוֹחִית שֶׁפִּיהָ צַר, טוֹבֵל וּמַעֲלֶה כְדַרְכּוֹ. רַבִּי יְהוּדָה אוֹמֵר, הַזָּיָה רִאשׁוֹנָה. מֵי חַטָּאת שֶׁנִּתְמַעֲטוּ, טוֹבֵל אֲפִלּוּ רָאשֵׁי גִבְעוֹלִין וּמַזֶּה, וּבִלְבַד שֶׁלֹּא יְסַפֵּג. נִתְכַּוֵּן לְהַזּוֹת לְפָנָיו וְהִזָּה לְאַחֲרָיו, לְאַחֲרָיו וְהִזָּה לְפָנָיו, הַזָּיָתוֹ פְסוּלָה. לְפָנָיו, וְהִזָּה עַל הַצְּדָדִין שֶׁלְּפָנָיו, הַזָּיָתוֹ כְשֵׁרָה. מַזִּין עַל הָאָדָם מִדַּעְתּוֹ וְשֶׁלֹּא מִדַּעְתּוֹ. מַזִּין עַל הָאָדָם וְעַל הַכֵּלִים, וַאֲפִלּוּ הֵן מֵאָה:
If one sprinkled, but there is a doubt as to whether [he sprinkled] from the string or from the rod [used to lengthen the short hyssop], or from the stalk [of the hyssop itself], his sprinkling is invalid. If one sprinkled onto two vessels, but there is a doubt as to whether he sprinkled on both of them [from the hyssop], or [that the water on one of them splashed] from its fellow [vessel] and onto it, his sprinkling is invalid. A needle which was placed on earthenware, if one sprinkled onto it, but there is a doubt as to whether he sprinkled on the needle, or [that the water splashed] from the earthenware onto it, his sprinkling is invalid [i.e. the needle remains impure]. A flask with a narrow mouth [containing <i>chatat</i> water], one dips [the hyssop in] and raises it out as usual. Rabbi Yehuda says: [only] the first sprinkling [can be done regularly; but for later sprinklings, there is a concern that hyssop will stick in the mouth of the flask and only absorb from the walls, and there might not be a proper dipping]. <i>Chatat</i> waters which became diminished [i.e. started running out], one dips even the tips of the stalks, and sprinkles, as long as it is not absorbing [water from the sides or bottom of the vessel, since there must be dipping]. If one intended to sprinkle forward and he sprinkled backwards, [or] backwards and he sprinkled forwards, his sprinkling is invalid; forward and he sprinkled to the sides in front of him, his sprinkling is valid. A person maybe be sprinkled, whether with his awareness, or without it. We sprinkle on a person and on vessels, even a hundred [in one sprinkling, so long as some water reaches them, with the sprinkler's intention].