Itztli

Itztli is the obsidian sacrificial knife made into a person, the second of the nine Lords of the Night and, in most colonial era sources, read as an aspect or manifestation of Tezcatlipoca, the smoking mirror god whose many faces include this one cut from volcanic glass. His name is the plain Nahuatl word for obsidian, the black stone struck into blades sharp enough to open flesh, and the Codex Borbonicus and related tonalamatl paintings show him with a flint or obsidian knife for a face or headdress, a figure that is the instrument of sacrifice rather than a separate personality standing apart from it.

Sahagun's account links him to the day sign Tecpatl, flint, one of the four year bearers, and Aztec thought regularly treated the tool used in a rite and the power behind the rite as continuous with each other, so Itztli was not merely equipment personified but a genuine object of address in prayer and offering before the blade was used. Duran's description of the sacrificial rites at the templo mayor gives some sense of the reverence and dread attached to the obsidian knife itself, kept and handled as a thing with its own force, wiped clean and stored rather than discarded, and Itztli is the theological expression of that handling. His place among the night lords, following Xiuhtecuhtli's fire, reads as a pairing familiar across the pantheon, since fire and the blade both cut and consume, and both were instruments the Mexica treated as active participants in ritual rather than inert tools.

Sources Florentine Codex: General History of the Things of New SpainBernardino de Sahagun; translated by Arthur J. O. Anderson and Charles E. Dibble with Book of the Gods and Rites and The Ancient CalendarDiego Duran; translated by Fernando Horcasitas and Doris Heyden

As the second of the nine Yohualteuctin, Itztli governs every ninth date beginning from the second day of the tonalpohualli, a plain rotation running beneath the 260 day count and unconnected to which of the twenty day signs or which trecena a given date falls under. A reader consulting the tonalamatl needed all three registers together, the day sign's own character, the trecena's overall augury as set by its patron pair, and the night lord's turn, to give a complete reading for a birth or an undertaking, and Sahagun's account of the calendar priests, the tonalpouhque, describes exactly this layered consultation rather than any single figure deciding a day's fortune alone.

Itztli's nights were read with the blade's own double character, since obsidian cuts equally for harm and for the letting of blood that Mexica ritual required of penitents and priests as an offering short of full sacrifice, so his presence in a reading carried both a caution and a call to disciplined ritual observance rather than a single fixed omen. Because the night lord cycle of nine shares no common factor with the 260 day tonalpohualli, Itztli's turn falls on a different day sign and a different trecena each time it recurs within a given 260 day round, so no fixed pairing of Itztli with any one day sign existed; the two counts simply interlock and re-align only once every 2340 days, the true period after which every combination of number, day sign and night lord returns to its start.

Sources Cycles of Time and Meaning in the Mexican Books of FateElizabeth Hill Boone with Florentine Codex: General History of the Things of New SpainBernardino de Sahagun; translated by Arthur J. O. Anderson and Charles E. Dibble