This sometimes led to innocent parties being punished. An accused who was able to flee to the nearest monastery would be protected from such mob justice. Sanctuary would give him an opportunity to explain himself and allow his accusers to calm down so that the facts could be more objectively examined.
The monks in the monastery the accused had sought sanctuary in would also be able to adjudicate on the accursed behalf. Numerous documents from ancient Sri Lanka show that royal officers and others were forbidden to enter certain monasteries or sometimes even monastic estates, to apprehend offenders without permission of the monks.
If the monks decided the person seeking refuge was guilty they would expel him or allow royal officers to enter the monastery to arrest him. On other occasions they might negotiate a settlement between the accused and his victim and the judicial authorities.
It might have been breaking the most serious of the five Precepts or five of the six ‘acts of immediate retribution’ (anantariyakamma, Miln.25), i.e. murdering one’s mother, one’s father, an arahat, injuring a Buddha or causing a schism in the Saṅgha (As.358).
In this context injuring a Buddha was understood to as stealing or desecrating a Buddha statue or other sacred objects. Other versions of the five grave offences included assault, killing cattle, banditry and rape.
The Mahavaṃsa records an example of this.
In response to this protest riots broke out in the capital, sections of the army rebelled and the life of the king himself was threatened. To calm the situation the king had to send his senior ministers after the monks to beg for their forgiveness and plea with them to return to their monastery.
There is nothing in the Tipiṭaka addressing the matter of sanctuary in monasteries although it is may have evolved from a general respect for the Saṅgha and the Buddha’s teaching allotting punishment with compassion.