nemiliztli.

cemihcac yoliliztli, in cemihcac nemiliztli = eternal life
Susanne Klaus, Uprooted Christianity: The Preaching of the Christian Doctrine in Mexico, Based on Franciscan Sermons of the 16th Century Written in Nahuatl (Bonn: Bonner Amerikanistische Studien e. V. c/o Seminar für Völkerkunde, Universität Bonn, 1999), 248.

in toTecuiyo Iesu Xpo in huel nelli çemihcac nemilizameialtzintli in itechpatzinco huel meya in ix uich yn teotequaltiliztli gracia = our lord Jesus Christ is the true eternal fountain of life from which really gushes all divine amelioration, grace
Andrés Sáenz de la Peña, Manual de los Santo Sacramentos, 1643, f. 34r.; translation by Mark Z. Christensen, "Nahua and Maya Catholicisms: Ecclesiastical Texts and Local Religion in Colonial Central Mexico and Yucatan," Ph.D. Dissertation, Pennsylvania State University, 2010, Appendix E, 14.

yn yecnemiliznemachtilizamatl = the book teaching proper living (scripture)
Andrés Sáenz de la Peña, Manual de los Santo Sacramentos, 1643, f. 35r.; translation by Mark Z. Christensen, "Nahua and Maya Catholicisms: Ecclesiastical Texts and Local Religion in Colonial Central Mexico and Yucatan," Ph.D. Dissertation, Pennsylvania State University, 2010, Appendix E, 16.

mitoa tlilotoc tlapalotoc yn nemiliztli = thus was it said: “The way of life is [according to] the black, the red [writings].” (central Mexico, sixteenth century)
Fray Bernardino de Sahagún, Primeros Memoriales, ed. Thelma D. Sullivan, et al. (Norman: University of Oklahoma Press, 1997), 228.

Intlil, intlapal in ueuetque. Inin tlatolli, itechpa mitoaya in intlamanitiliz in ueuetque, in tlein oquitlaliteoaque nemiliztli. = The black and red of the ancients. This was said of the traditions of the ancients, the way of life they established.
Thelma D. Sullivan, "Nahuatl Proverbs, Conundrums, and Metaphors, Collected by Sahagún," Estudios de Cultura Náhuatl 4 (1963), 172–173.

"..."the black the red of the ancients" refers (among other things) to the well-arranged, well-spread-out nemiliztli or "lifeway." As with so many of the principal concepts of Nahua philosophy, I suspect that maize horticulture is at the root of the notion of tlamanitiliztli and the well-arranged nemiliztli: in this case, the careful measuring, extending, arranging and spreading out of a milpa and the seeds in the milpa...[and] the good (cualli) milpa not only consists of but actively enacts the proper interrelationship between seeds, earth, sun, shade, and water." And is a subsequent message the same day, "Extrapolating from Sahagún's informants' remarks regarding good artisanship, I suggest that good/wise – “the black the red” -- tlamanitiliztli configured nemiliztli (like the well-fabricated fabric and featherwork, and well-composed song and poetry) consists in humans being spread out and extended in such a manner as to minimize (and ideally eliminate): (a) social (interpersonal) discord, disquiet, derangement, and disharmony; (b) the presence of tears, rips, snags, holes, gaps, frays, wrinkles, obstructions, and tangles in the social fabric (society); and, as a consequence, (c) minimize personal physical-psychological discord, imbalance, disharmony and sickness."
Personal communication, James Maffie, 9 June 2023.