In the Thai language a hermit is called a Lersi (reusee) and in Khmer a rosei from Sanskrit rishī, that is, a forest dwelling visionary. As a matter of fact, in the oldest surviving Buddhist scriptures, the Buddha himself is referred to as the "Rishī" in the Pali form Isi.
In general Lersi are known as 'Ascetics' and are characterised by refraining from worldly pleasures. Those who practice this lifestyle hope to achieve greater spirituality. Essentially they believe that the action of purifying the body helps to purify the soul, and thus obtain a greater connection with the divine.
Originating in India before the time of Buddha most are hermits and live, study and meditate in caves or forests.
Essentially Phra Lersi are Indian hermits who are credited as founders and patron saints of various professions such as doctors, religious tattooists, white magic practitioners, herbalists and many others. There are a total of 108 scared Lersi (hermits) that are recognized by name and many others who are not. More often than not the Lersi is generically represented as an old man wearing a conical head dress and tiger skin robes.
In Indian mythology, Phra Lersi received worldly knowledge from the Gods and taught this to mankind. Thus Phra Lersi are known as Masters of knowledge and are frequently worshipped by students and others in academic pursuits. As Phra Lersi are also credited to be founders of the Thai magical arts, they feature prominently on the alters of magical practitioners in Thailand and are invoked in rituals.
By carrying the image of Phra Lersi it is believed that you will be protected from black magic and evil spirits.