As dawn broke, a disciple walked with the Zen master along a rocky path.
Suddenly, a bird sang from a nearby tree. The master stopped walking and asked, — "Do you hear that bird singing?"
The disciple nodded, and the master asked — "Why do you think it sings?"
The disciple pondered various reasons related to nature, survival, and mating rituals but could not settle on an answer.
He finally conceded — "I do not know, Master. Why does it sing?"
The master continued walking as he replied — "The bird sings because it has a song.”