Carmen Arvale
Mars · the LaresThe song of the Arval Brethren, cut in stone in AD 218 as part of the record of their rite — the oldest continuous Latin text that has come down to us.
The essential thing about it is that the priests of the third century sang it no longer understanding the words. The stone preserves not a text but a performance: each verse three times, triumpe five times — and the spelling drifts between repetitions (pleores / pleoris, sins / sers, semunis / simunis), because the scribe was writing down a sound he could not parse.
What we have, strictly speaking, is a recording rather than a document. Hence the reading remains largely conjectural: sta berber has never been convincingly translated, and the Russian gives a tentative "stand, strike".
A living liturgy can outlive its own language by centuries and go on working by sound alone. The Arval song is the purest evidence of this in Latin.