Reference for Zavim 5:2
וְעוֹד כְּלָל אַחֵר אָמְרוּ. כֹּל הַנִּשָּׂא עַל גַּבֵּי הַזָּב, טָמֵא. וְכֹל שֶׁהַזָּב נִשָּׂא עָלָיו, טָהוֹר, חוּץ מִן הָרָאוּי לְמִשְׁכָּב וּלְמוֹשָׁב וְהָאָדָם. כֵּיצַד. אֶצְבָּעוֹ שֶׁל זָב תַּחַת הַנִּדְבָּךְ, הַטָּהוֹר מִלְמַעְלָן, מְטַמֵּא שְׁנַיִם וּפוֹסֵל אֶחָד. פֵּרַשׁ, מְטַמֵּא אֶחָד וּפוֹסֵל אֶחָד. הַטָּמֵא מִלְמַעְלָן וְהַטָּהוֹר מִלְּמַטָּן, מְטַמֵּא שְׁנַיִם וּפוֹסֵל אֶחָד. פֵּרַשׁ, מְטַמֵא אֶחָד וּפוֹסֵל אֶחָד. הָאֳכָלִין וְהַמַּשְׁקִין, הַמִּשְׁכָּב, וְהַמּוֹשָׁב וְהַמַּדָּף מִלְמַעְלָן, מְטַמְּאִין שְׁנַיִם וּפוֹסְלִין אֶחָד. פֵּרְשׁוּ, מְטַמְּאִין אֶחָד וּפוֹסְלִין אֶחָד. וְהַמִּשְׁכָּב וְהַמּוֹשָׁב מִלְּמַטָּן, מְטַמְּאִין שְׁנַיִם וּפוֹסְלִין אֶחָד. פֵּרְשׁוּ, מְטַמְּאִין שְׁנַיִם וּפוֹסְלִין אֶחָד. הָאֳכָלִין וְהַמַּשְׁקִין וְהַמַּדָּף מִלְּמַטָּן, טְהוֹרִין:
Another general rule they said, Anything that is carried above a <i>zav</i> [even though there is no contact] becomes unclean and all things above which he [the <i>zav</i>] is carried is clean except objects on which he can sit or lie upon and a person. How so [does this law apply]? [If] the finger of a <i>zav</i> was under a layer of stones and one [a person] that is clean is [sitting] above, he renders unclean at two [levels] and renders unfit [terumah] at one [level more]. If he separated himself [from the source of unclenaliness], he renders unclean at one [level] and renders unfit [terumah] at one [level more]. If the unclean one was above, and the clean one below, he renders unclean at two [levels], and disqualifies [terumah] at one [level more]. If he separated himself [from the source of uncleanness], he renderds unclean at one [level] and renders unfit [terumah] at one [level more]. [If] food, liquids or objects on which he can sit or lie upon or <i>madaf</i> [other articles] were above [the <i>zav</i>], he renders unclean at two [levels], and disqualifies [terumah] at one [level more]. If he separated himself [from the source of uncleanness], he renderds unclean at one [level] and renders unfit [terumah] at one [level more]. If objects on which he can sit or lie upon were below [the <i>zav</i>], he renders unclean at two [levels], and disqualifies [terumah] at one [level more]. If he separated himself [from the source of uncleanness], he renderds unclean at two [levels] and renders unfit [terumah] at one [level more]. If food, liquids and a <i>madaf</i> are below they are clean.