Kumbhasutta
“Cattārome, bhikkhave, kumbhā. Katame cattāro? Tuccho pihito, pūro vivaṭo, tuccho vivaṭo, pūro pihito— Ime kho, bhikkhave, cattāro kumbhā. Evamevaṁ kho, bhikkhave, cattāro kumbhūpamā puggalā santo saṁvijjamānā lokasmiṁ. Katame cattāro? Tuccho pihito, pūro vivaṭo, tuccho vivaṭo, pūro pihito.
Pots
“Mendicants, there are these four pots. What four? Covered but hollow, uncovered but full, uncovered and hollow, and covered and full. These are the four pots. In the same way, these four individuals similar to pots are found in the world. What four? Covered but hollow, uncovered but full, uncovered and hollow, and covered and full.