The story tells that on one occasion, the Buddha was staying at the Jetavanna monastery along with monks. On one Uposatha day, the people of Savatthi who were faithful went to the monastery to observe Uposatha precepts and listen to the Buddha’s sermon. At night of the day, the monks and people were practicing in the darkness. There was a woman bringing a lamp, she lighted it there in order to make light for the monks and people doing their practices easier. When she died, the merit of making the light supported her to happen in Tavatimsa heaven with a crystal castle of 16 yojana height illuminating like the moonlight.