four special events happened:
1. There were 1,250 Sangha followers decided to come back to see Lord Buddha at Weluwan Wannaram without prior appointment after traveling around and teaching Buddhism.
2. All of them were “อรหันต์ Arhantas’, the Enlightened One, and all of them were ordained by the Buddha himself.
3. Because it was the first assembly of the large group of the Buddhist monk gathering therefore the Buddha gave those Arhantas the three principles of the Buddhism, called “The Ovadhapatimokha” which is considered the first constitution for all the laws of Buddhist monks from then until now.
4. It was the full moon day.