Reference for Yadayim 3:1
הַמַּכְנִיס יָדָיו לְבַיִת הַמְנֻגָּע, יָדָיו תְּחִלּוֹת, דִּבְרֵי רַבִּי עֲקִיבָא. וַחֲכָמִים אוֹמְרִים, יָדָיו שְׁנִיּוֹת. כֹּל הַמְטַמֵּא בְגָדִים בִּשְׁעַת מַגָּעוֹ, מְטַמֵּא אֶת הַיָּדַיִם לִהְיוֹת תְּחִלּוֹת, דִּבְרֵי רַבִּי עֲקִיבָא. וַחֲכָמִים אוֹמְרִים, לִהְיוֹת שְׁנִיּוֹת. אָמְרוּ לוֹ לְרַבִּי עֲקִיבָא, הֵיכָן מָצִינוּ שֶׁהַיָּדַיִם תְּחִלָּה בְכָל מָקוֹם. אָמַר לָהֶם, וְכִי הֵיאַךְ אֶפְשָׁר לָהֶן לִהְיוֹת תְּחִלָּה אֶלָּא אִם כֵּן נִטְמָא גוּפוֹ, חוּץ מִזֶּה. הָאֳכָלִין וְהַכֵּלִים שֶׁנִּטְמְאוּ בְמַשְׁקִין, מְטַמְּאִין אֶת הַיָּדַיִם לִהְיוֹת שְׁנִיּוֹת, דִּבְרֵי רַבִּי יְהוֹשֻׁעַ. וַחֲכָמִים אוֹמְרִים, אֶת שֶׁנִּטְמָא בְאַב הַטֻּמְאָה, מְטַמֵּא אֶת הַיָּדַיִם. בִּוְלַד הַטֻּמְאָה, אֵינוֹ מְטַמֵּא אֶת הַיָּדַיִם. אָמַר רַבָּן שִׁמְעוֹן בֶּן גַּמְלִיאֵל, מַעֲשֶׂה בְאִשָּׁה אַחַת שֶׁבָּאָת לִפְנֵי אַבָּא, אָמְרָה לוֹ, נִכְנְסוּ יָדַי לַאֲוִיר כְּלִי חֶרֶשׂ. אָמַר לָהּ, בִּתִּי, וּבַמֶּה הָיְתָה טֻמְאָתָהּ, וְלֹא שָׁמַעְתִּי מָה אָמְרָה לוֹ. אָמְרוּ חֲכָמִים, מְבֹאָר הַדָּבָר. אֶת שֶׁנִּטְמָא בְאַב הַטֻּמְאָה, מְטַמֵּא אֶת הַיָּדַיִם. בִּוְלַד הַטֻּמְאָה, אֵינוֹ מְטַמֵּא אֶת הַיָּדָיִם:
If one's hand enters into a blighted house [i.e. a leperous house], the hands are [rendered to be of a] primary [degree of impurity], according to Rabbi Akiva. And the Sages say: the hands are [rendered with a] secondary [degree of impurity]. Anything that renders garments impure instantly upon contact, renders the hands to be of a primary [degree of] impurity, according to Rabbi Akiva. And the Sages say: [it renders the hands] to be [of a] secondary [degree of impurity]. They said to Rabbi Akiva, "Where is there any place that we find that the hands are [rendered impure in a] primary [degree]?" He said to them, "And how [else] is it possible that they can be rendered [impure in a] primary [degree] without one's body having been rendered impure, except in this instance!" Food items and vessels which were rendered impure by liquids, render the hands to be of a secondary [degree of] impurity, according to Rabbi Yehoshua. And the Sages say: that which was rendered impure by an Origin of impurity renders the hands impure; [and that which was rendered impure] by a derivative impurity does not render the hands impure. Rabbi Shimon ben Gamliel said, "It happened that a woman came before my father, and said to him, 'My hands entered into the air-space of an [impure] earthenware vessel.' He said to her, 'My daughter, through what was its impurity [caused]?' But I did not hear what she said to him." The Sages said, "The matter is elucidated: that which was rendered impure by an Origin of impurity renders the hands impure; [and that which was rendered impure] by a derivative impurity does not render the hands impure."