Butter lamps are a one of the important part of Hindu and Buddhist Temples and Monastery throughout Nepal. The lamps traditionally burn clarified yak butter, but now often use vegetable oil or vanaspati ghee.
Buddhist of Nepal offer a lighted butter lamp, representing the illumination of wisdom,, or Removing ignorance with wisdom. along with seven bowls containing pure water before the images on their household shrine. The butter lamp usually being placed between the fourth and fifth bowls. At funeral ceremonies or when visiting temples and going on pilgrimage to sacred sites, 
The butter lamps help to focus the mind and aid meditation 
the lights are seen to banish darkness. Conceptually, they convert prosaic substance into illumination, a transformation akin to the search for enlightenment. Esoterically, they recall the heat of the tummo yoga energy of the Six Yogas of Naropa, an important text for Kagyu, Gelug, and Sakya schools of tantric Buddhism.