Reference for Zavim 5:1
הַנּוֹגֵעַ בַּזָּב אוֹ שֶׁהַזָּב נוֹגֵע בּוֹ, הַמַּסִּיט אֶת הַזָּב אוֹ שֶׁהַזָּב מַסִּיטוֹ, מְטַמֵּא אֳכָלִים וּמַשְׁקִים וּכְלֵי שֶׁטֶף בְּמַגָּע, אֲבָל לֹא בְמַשָּׂא. כְּלָל אָמַר רַבִּי יְהוֹשֻׁעַ, כָּל הַמְטַמֵּא בְגָדִים בִּשְׁעַת מַגָּעוֹ, מְטַמֵּא אֳכָלִים וּמַשְׁקִין לִהְיוֹת תְּחִלָּה, וְהַיָּדַיִם לִהְיוֹת שְׁנִיּוֹת, וְאֵינוֹ מְטַמֵּא לֹא אָדָם וְלֹא כְלֵי חֶרֶס. לְאַחַר פְּרִישָׁתוֹ מִמְּטַמְּאָיו, מְטַמֵּא מַשְׁקִין לִהְיוֹת תְּחִלָּה, וְהָאֳכָלִין וְהַיָּדַיִם לִהְיוֹת שְׁנִיּוֹת, וְאֵינוֹ מְטַמֵּא בְגָדִים:
If one [who is clean] touches a <i>zav</i> or if a <i>zav</i> touches him, [or] if one moves a <i>zav</i>, or if a <i>zav</i> moves him, he renders unclean food, drink and utensils that can be rinsed [immersed in a mikva and thereby made clean] through touch, but not through carryinng. Rabbi Yehoshua stated [the following] general principle, Anyone that renders garments unclean while in contact [with the source of his uncleanliness], renders unclean food and liquids to become a first level uncleanliness and the hands to become a second level of uncleanliness, and does not render unclean people or earthenware vessels. After he has separated from the source of his uncleanliness, he renders unclean liquids to become a first level uncleanliness, and food and hands to become a second level of uncleanliness, and he does nor tender garments unclean.