a deity relating to fire; this "Yellow Face" was more commonly called Xiuhteuctli (or Xiuhtecuhtli), "Turquoise Lord," and Huehueteotl, "Old God" Fray Bernardino de Sahagún, Primeros Memoriales, ed. Thelma D. Sullivan, et al. (Norman: University of Oklahoma Press, 1997), 100.
"Yellow Face" was part of the Xiuhtecuhtli Complex of deities, associated with fire and paternalism "Table 3. Major Deities of the Late Pre-Hispanic Central Mexican Nahua-Speaking Communities." Handbook of Middle American Indians, Volume 6: Social Anthropology, ed Manning Nash (Austin: University of Texas Press, 1967).
a flint knife used to cut open the breast of a captive for extracting the heart in a human sacrifice, such as upon drilling the fire at the start of a new 52-year cycle Fr. Bernardino de Sahagún, Florentine Codex: General History of the Things of New Spain; Book 7 -- The Sun, Moon, and Stars, and the Binding of the Years, Number 14, Part 8, eds. and transl. Arthur J. O. Anderson and Charles E. Dibble (Santa Fe and Salt Lake City: School of American Research and the University of Utah, 1953), 28.