Mishnah Oholot 8:3-4

אֵלּוּ מְבִיאִין וְלֹא חוֹצְצִין. הַשִּׁדָּה, וְהַתֵּבָה, וְהַמִּגְדָּל, כַּוֶּרֶת הַקַּשׁ, כַּוֶּרֶת הַקָּנִים, וּבוֹר סְפִינָה אֲלֶכְּסַנְדְּרִית, שֶׁאֵין לָהֶם שׁוּלַיִם וְאֵינָן מַחֲזִיקִים אַרְבָּעִים סְאָה בְלַח, שֶׁהֵם כּוֹרַיִם בְּיָבֵשׁ. וִירִיעָה, וּסְקוֹרְטְיָא, וּקְטָבֹלְיָא, וְסָדִין, וּמַפָּץ, וּמַחֲצֶלֶת, שֶׁאֵין עֲשׂוּיִין אֹהָלִים, וּבְהֵמָה וְחַיָּה שֶׁמֵּתוּ, וְאֳכָלִים טְמֵאִים. מוּסָף עֲלֵיהֶם, הָרֵחַיִם שֶׁל אָדָם:

The following bring [impurity] but do not protect against it: A chest, a box, a cupboard, a beehive of straw, a beehive of reeds, or the water tank of an Alexandrian ship, such of which [objects] have [flat] bottoms but cannot contain forty se'ahs of liquid measure or two kors dry measure. A curtain, a leather apron, a leather undercover, a sheet, a matting underlay or a mat when not made into tents. Cattle or wild animals when they are dead, and foodstuffs that are [liable to become] unclean. In addition to these, a human-powered mill.

אֵלּוּ חוֹצְצִים וְלֹא מְבִיאִין. מַסֶּכֶת פְּרוּסָה, וַחֲבִילֵי הַמִּטָּה, וְהַמִּשְׁפָּלוֹת וְהַסְּרִיגוֹת שֶׁבַּחֲלוֹנוֹת:

The following protect [against impurity] but do not bring it: A loom [with the woof] spread out, the ropes of a bed, waste baskets, and window-lattices.