Ra and La in the Older Language and the Prakrits

The relationship between the two liquids is one of the standard dialect markers of early Indo-Aryan. The Vedic language favours r where the later classical language and several of the Prakrits favour l, and the distribution differs by region, so a word appearing with one liquid in one text and the other elsewhere is usually evidence about where or when the text was made rather than about two separate words.

That matters for Buddhist material specifically, because the Buddhist literature was not composed in classical Sanskrit to begin with. It draws on the spoken languages of northern India, it was transmitted through several of them, and a good deal of it was later reworked into Sanskrit of varying degrees of regularity. Words carrying the marks of a Prakrit origin survive throughout, and the liquids are among the clearest of those marks.

A script cannot resolve any of this and does not try to. Siddham writes what a scribe put in front of it, and the letter that stands on the page is evidence about the exemplar rather than about the word as any grammarian would have wanted it. That is a general property of manuscript evidence and it is why an edition of a Buddhist text is a reconstruction of a transmission rather than of an original.