huehuetlatolli.

Apparently alone in its category anywhere in the Spanish colonies is the "Huehuetlahtolli" of 1600 of fray Juan Batista and the trilingual (Latin/Nahuatl/Spanish) Nahua teacher Agustín de la Fuente. In the main it is a revised version of material written down in the 1540's. The book illustrates many of the modalities of the polite upper-class metaphorical Nahuatl known as "huehuetlahtolli",
See Sell's comments in Bartolomé de Alva, A Guide to Confession Large and Small in the Mexican Language, 1634, eds. Barry D. Sell and John Frederick Schwaller, with Lu Ann Homza (Norman: University of Oklahoma Press, 1999), 19.

yn ticneltilia yn ticchicahua huehuetlahtolli = as we authenticate and affirm the ancient ones' accounts (central Mexico, early seventeenth century)
Codex Chimalpahin: Society and Politics in Mexico Tenochtitlan, Tlatelolco, Culhuacan, and Other Nahuatl Altepetl in Central Mexico; The Nahuatl and Spanish Annals and Accounts Collected and Recorded by don Domingo de San Antón Muñón Chimalpahin Quauhtlehuanitzin, eds. and transl. Arthur J. O. Anderson and Susan Schroeder (Norman: University of Oklahoma Press, 1997), vol. 1, 64–65.

huehuehtlahtolli = "'old speech' or 'words of the elders.' The elite claimed particular mastery of this prestigious verbal art form." "The new plays were based on sacred narratives; the new written scripts imitated huehuehtlahtolli style."
Louise M. Burkhart, Holy Wednesday: A Nahua Drama from Early Colonial Mexico (Philadelphia: University of Pennsylvania Press, 1996), 44, 45.

huehuetlahtolli = variously translated by those studying it as "the old word," "the speeches/admonitions of the elders," or "the ancient discourse"
See Sell's comments in Bartolomé de Alva, A Guide to Confession Large and Small in the Mexican Language, 1634, eds. Barry D. Sell and John Frederick Schwaller, with Lu Ann Homza (Norman: University of Oklahoma Press, 1999), 19.