Upatissa asked Venerable Assaji: "What is the teaching
of the Buddha?" Assaji replied: "I will tell you
the meaning of the Buddha's teaching very briefly. The Buddha
said that there is a cause for everything and he also taught
how things decay." Upatissa was so clever that when he
heard this he understood that whatever comes into existence
will also decay, and he attained the first stage of enlightenment.
Then he thanked Assaji, asked him where he might find the
Buddha, and left.