The artwork comprises three characters, a boy, a gentleman, and an older man. The painting is considered an allegory of life's three stages, respectively youth, adulthood and the elderly. The title of the painting describes the age difference between the three characters. Although some scholars consider the theme of the painting to be a music lesson, others believe it's the episode of Jesus meeting a rich young man. The older character is believed to be St. Peter. The extraordinary elements of the painting are the character's garments. They provide the main clues of the painting's subject.
The young man has golden lapels on his clothes, which indicate that he is wealthy. He's holding a piece of parchment, but you cannot decipher the writing. It's thought to be the 10 Commandments. The man on the right is the interpretation of Jesus. Giorgione doesn't paint a halo or a nimbus to reflect this. But the pointed finger is a clear indication of the man's identity. It's believed that Jesus is pointing at the 10 Commandments written on the paper. Jesus is wearing green clothing, which resembles a robe worn by priests during Mass.
The older man is believed to be St Peter. He's on the left side of the painting, looking towards the viewer. Giorgione uses the character to draw the viewers and to promote direct participation in the painting's theme. The colour of St Peter's clothing is also significant. His robe is red, which is the colour of robes worn during the feast days. The old man's physiognomy is a traditional reinterpretation of St Peter. He has a bald head and a short beard. Painters often portray St Peter as being a robust elderly man, with raw features.
The Three Ages of Man by Giorgione is a reinterpretation of Jesus' encounter with a young man, who is wondering what he can do to receive the gift of Eternal life. Jesus points to the 10 Commandments and tells the young man to give his riches to the poor and he shall receive great fortune in Heaven. The young man is saddened as he has many riches. Although scholars have offered various other interpretations of the painting, Giorgione has left certain clues, which indicate the biblical theme.