Stories Relating to Anicca, Dukkha and Anatta

While residing at the Jetavana monastery, the Buddha uttered Verses (277), (278) and (279) of this book, with reference to three groups of five hundred bhikkhus each.
On Impermanence (Anicca)
Five hundred bhikkhus, after receiving their subject of meditation from the Buddha, went into the forest to practise meditation, but they made little progress. So, they returned to the Buddha to ask for another subject of meditation which would suit them better. On reflection, the Buddha found that those bhikkhus had, during the time of Kassapa Buddha, meditated on impermanence. So, he said, "Bhikkhus, all conditioned phenomena are subject to change and decay and are therefore impermanent."
At the end of the discourse those five hundred bhikkhus attained arahatship.
On Insubstantiality or Non-Self (Anatta)
The story is the same as the stories on Anicca and Dukkha. Here, the Buddha on reflection found that still another group of five hundred bhikkhus had meditated on insubstantiality or non-self (anatta). So, he said, "Bhikkhus, all khandha aggregates are insubstantial; they are not subject to one's control."
At the end of the discourse all those five hundred bhikkhus attained arahatship.
On Dukkha
The story is the same as the story on Anicca. Here, the Buddha on reflection found that another group of five hundred bhikkhus had meditated on dukkha. So, he said, "Bhikkhus, all khandha aggregates are oppressive and unsatisfactory; thus all khandhas are dukkha."
At the end of the discourse those five hundred bhikkhus attained arahatship.
Then the Buddha spoke in verse as follows: