Keilim19: 7
תֵּבָה שֶׁפִּתְחָהּ מִלְמַעְלָה — טְמֵאָה טְמֵא מֵת. נִפְחֲתָה מִלְמַעְלָה — טְמֵאָה טְמֵא מֵת. נִפְחֲתָה מִלְּמַטָּה — טְהוֹרָה. מְגוּרוֹת שֶׁבָּהּ — טְמֵאוֹת, וְאֵינָם חִבּוּר לָהּ.
A chest whose opening is on top [can become] tamei with corpse-tumah. If it became damaged at [its] top, it [can become] tamei with corpse-tumah. If it became damaged at [its] bottom, it is tahor. Its compartments are tamei and are not considered connected to it.