Magha Puja commemorates an assembly that was not organised: 1,250 arhats, all ordained by the Buddha himself, arrived at the same place on the same full moon without being summoned, and he delivered a summary of the teaching to them. Asalha Puja marks the first sermon and opens the rains retreat the following day. In Thailand both are public holidays and both are observed the same way — the laity gather at dusk and circle the main hall three times carrying candles, incense and a flower, once each for the Buddha, the dharma and the sangha. It is the most photographed thing Thai Buddhism does, and the least explained.