More specifically, how widespread were the cremation rites as compared to the regular burial grounds and did they have any specific social and symbolic significance?
It seems to me it is quite understandable that the cremation was the more expensive and hence the more prestigious burial method. Considering specifically the Buddha’s funeral, it helped prevent the sacred body of the Enlightened One from decomposing and coming in contact with beings considered impure at the times (insects, worms, yakkhas, etc.). On the other hand, the fire imagery is a constant theme in the Buddha’s sermons. One can mention such prominent texts and images as the Fire Sermon, possible fire metaphor used in describing the khandhas, and of course the Nibbana itself. Could the cremation be considered by some (most likely not by the monastics versed in the Teaching) as a necessary step in the Master’s parinibbana, as his dead body, being one of the khandhas composing him during his lifetime, required ‘stilling’ just as much as his mind? The relics of the Buddha and other saints, remaining after such a ceremony, could easily be taken by people having such views to be ‘not quite the body’ of the deceased but rather a visible manifestation of the Transcendental in the samsaric world (cf. with the contemporary sariras).
The cremation ceremony is reported to have been carried out by the laity, most of whom probably did not even think of themselves as a religous dispensation distinct from the dominant Brahmanism of the time, so the popular theories about the significance of the body, specifically of a Sacred Body, could have played a role. Moreover, imitation of this funeral ceremony and its application to ordinary people (most likely in the broader Brahmanist rather than in the specifically Buddhist context) could have contributed to the predominance of cremation in the modern Indic religious traditions.
This is all wildly speculative and most probably false in all or some of the suggestions, but still too intriguing to me not to ask about it. I would be very happy to hear what more knowledgeable people than me with a more solid background in the studies of the Canon and Ancient Indic culture have to say about it.
According to early Buddhist literature, the most common place for disposing of a dead body seems to have been the charnel ground (susāna/sivathika), that is, a place where bodies are just left to rot and decompose. You can gather that charnel grounds must have been quite common from the fact that charnels grounds are one of the places monastics were recommended to find solitude and because the cemetery contemplations (really, charnel ground contemplations) are one of the meditations mentioned in the suttas. The charnel ground was also a place where rag-robe wearing monastics would get rags by removing cloth from the corpses (hopefully not too decayed!).
By contrast, the burning of corpses is rarely mentioned in the suttas. You find it, of course, in the Mahāparinibbāna Sutta, with the burning of the body of the Buddha. You also find it in the Nāradasutta (AN 5.50), which Bhante Sujato has suggested may be the latest sutta in the Pali canon. The person cremated here was a queen. The (unsuccessful) cremation of a (still living!) monk is mentioned in MN 50. All of these cases seem to suggest that cremation was most common for people of high social status.
There is also the word āḷāhana, which seems to mean “place of cremation”. This word is used in the description of the doctrine of Ajitakesakambala (e.g. at DN 2), where a corpse is said to be carried as far as the āḷāhana. It is also found in MN87, where a man is said to go to the āḷāhana, longing for his dead son.
As for burial, I am not sure if there is any evidence for this at all in the suttas, apart from the stupas made for the Buddha’s relics and for the queen mentioned above. In the period after the Buddha’s passing away, there seems to be an increase in stupa making, especially for esteemed monastics. Such a stupa is mentioned in the origin story of the 52nd bhikkhunī pācittiya. In the Dharmagupta Vinaya there is a whole section on how one should behave around stupas.
So far. in what you said about the Ancient Indic funeral rites there is no evidence confirming my wild speculations, just as there is nothing proving them wrong. Most likely, cremation was not specifically Buddhist and was not reserved specifically for the Buddha. Hopefully, some scholar will be able to look into the matter one day as I don’t know about any maor work concerned solely with this problem and the origin of the relic cult. Thanks so much again!
There might be some helpful information for you in Daily Life In Ancient India. It discusses a later time, but I imagine there are still some commonalities.
