Buddhism, especially in the Pali canon of the Theravada school loves its lists and numbers. 108 is seen as a very special one in particular, as it refers to the number of defilements to overcome to gain enlightenment, and it is derived from the following formula:
The Three Sense Experiences X The Six Senses = 18
Aversion or Craving to these experiences = 18 X 2 = 36
Past, Future, and Present incidents of aversion of craving = 36 X 3 = 108
The three sense experiences are:
- good, ie pleasurable
- bad, ie unpleasant
- neutral, ie indifferent
The six senses are
(It should be noted that Buddhism considers that the mind is a sixth sense that senses thought objects.)
Temples will often have 108 steps for example, and malas (rosaries) usually have 108 beads.