"Buddhist Ceremonies and Rituals of Sri Lanka" states that Buddhists perform the Sri Lankan oil lamp ceremony to "acquire merit or to avert evil influence." As "Buddha is regarded as the dispeller of the darkness of ignorance," believers offer lighted lamps in his name.
The offering of lighted lamps, which usually contain coconut oil, has been an important ritual in Sri Lanka since ancient times and continues until the present day.
According to "Buddhist Ceremonies and Rituals of Sri Lanka," those taking part in the ceremony purify themselves beforehand by bathing and wearing fresh clothes. Flowers are also a part of the ritual. A whole village may collaborate in a ceremony offering many lamps to the Buddha.
Buddhist temples have a sheltered platform and special lamp stands that hold lighted oil lamps. The dolosmahe-pahana (12-month lamp) burns all year round.
Buddhists make special light offerings to commemorate special occasions such as Full Moon or Vesak Day (Buddha’s birthday). According to “Ira Handa: Sri Lanka Wedding Guidance,” couples light the traditional oil lamp to symbolize a bright future.
The ceremony is associated with the sacred Bodhi tree, under which the Buddha attained enlightenment. Believers light lamps under the tree in memory of the Buddha’s enlightenment and as a way of attaining wisdom.