Lakkhaṇasutta
“Kammalakkhaṇo, bhikkhave, bālo, kammalakkhaṇo paṇḍito, apadānasobhanī paññāti. Tīhi, bhikkhave, dhammehi samannāgato bālo veditabbo. Katamehi tīhi? Kāyaduccaritena, vacīduccaritena, manoduccaritena. Imehi kho, bhikkhave, tīhi dhammehi samannāgato bālo veditabbo.
Characteristics
“A fool is characterized by their deeds, and an astute person is characterized by their deeds, for wisdom shines in its traces. A fool is known by three things. What three? Bad conduct by way of body, speech, and mind. These are the three things by which a fool is known.